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OOMMF User's Guide

1. M x M x Hep where 7 is the Landau Lifshitz gyromagnetic ratio m A s a is the damping coefficient dimensionless Compare to 2 page 66 Here a is specified by the Damp Coef entry in the MIF 1 1 file If not specified a default value of 0 5 is used which allows the solver to converge in a reasonable number of iterations Physical materials will typically have a damping coefficient in the range 0 004 to 0 15 The 2D solver engine mmSolve Sec 10 requires a non zero damping coefficient 17 3 2 Demag specification e Demag Type Specify algorithm and demagnetization kernel used to calculate self magnetostatic demagnetization field Must be one of ConstMag Calculates the average field in each cell under the assumption that the magnetization is constant in each cell using formulae from 15 The other demag options calculate the field at the center of each cell 3dSlab Calculate the in plane field components using offset blocks of constant volume charge Details are given in 3 Field components parallel to the z axis are calculated using squares of constant surface charge on the upper and lower surfaces of the sample 3dCharge Calculate the in plane field component using rectangles of constant surface charge on each cell This is equivalent to assuming constant magnetiza tion in each cell The z components of the field are calculated in the same manner as for the 3dSlab approach
2. d i k out file target where d Print verbose information about dependencies i Normally an error halts operation When i is specified ignore errors and try to continue updating all dependencies of target k Normally an error halts operation When k is specified and an error is encountered stop processing dependencies which depend on the error but continue updating other dependencies of target out file Write output to named file instead of to the standard output target The file to build May also be and usually is a symbolic target name See below for standard symbolic targets By default the first target in makerules tcl is built There are several targets which may be used as arguments to pimake to achieve different tasks Each target builds in the current directory and all subdirectories The standard targets are upgrade Used immediately after unpacking a distribution it removes any files which were part of a previous release but are not part of the unpacked distribution all Creates all files created by the configure target see below Compiles and links all the executables and libraries Constructs all index files configure Creates subdirectories with the same name as the platform type Constructs a ocport h file which includes C header information specific to the platform objclean Removes the intermediate object files created by the compile and link steps Leaves working executables in place
3. 12 Data Graph Display mmGraph 13 Vector Field Display mmDisp 14 Data Archive mmArchive 15 Documentation Viewer mmHelp 16 Command Line Utilities 16 1 Bitmap File Format Conversion any2ppm 4 16 2 Making Data Tables from Vector Fields avf2odt 16 3 Vector Field File Format Conversion avf2ovf 00056 16 4 Making Bitmaps from Vector Pields av RppII e coe 4 46 hae e eee ees 16 5 Making PostScript from Vector Fields avf2ps 00056 16 6 Vector Field File Difference avfdiff 000000006 16 7 Cyclic Redundancy Check Gres2 lt soea sore eee ek m a t Re EEE Ore 16 8 Killing OOMMP Processes killoommi lt 62d 4 eee ae ee eases 16 9 Launching the OOMMF host server launchhost 16 10Calculating H Fields from Magnetization mag2hfield 2 16 11MIF Format Conversion mifconvert 0000 eee ne 10 120DT Column Fetraction Odile wc beeen pe Peewee eL ees 16 1300OMMEF and Process ID Information pidinfo 16 14Process Nicknames nickname 0 ee eee eee ns 16 15Platform Independent Make pimake 2 0 17 Problem Specification File For Piel Be a cee ewe eee ee mats MIF 17 1 1 MIF 2 1 File Overview 0 00 0 0 00000 bee eee 17 1 2 MIF 2 1 Extension Commands o o scs si edee cau Dekar aa 17 1 3 Specify Conventions ii 102 105 107 107 114 114 117 1
4. 17 3 1 Material parameters e Material Name This is a convenience entry for mmProbEd inside the MIF 1 1 209 file it is a comment line It relates a symbolic name e g Iron to specific values to the next 4 items Ignored by solvers Ms Saturation magnetization in A m A Exchange stiffness in J m K1 Crystalline anisotropy constant in J m If K1 gt 0 then the anisotropy axis or axes is an easy axis if K1 lt 0 then the anisotropy axis is a hard axis Anisotropy Type Crystalline anisotropy type One of lt uniaxial cubic gt Anisotropy Dir1 Directional cosines of first crystalline anisotropy axis taken with respect to the coordinate axes 3 numbers Optional Default is 1 0 0 x axis Anisotropy Dir2 Directional cosines of second crystalline anisotropy axis taken with respect to the coordinate axes 3 numbers Optional Default is 0 1 0 y axis For uniaxial materials it suffices to specify only Anisotropy Dirl For cubic materials one must also specify Anisotropy Dir2 the third axis direction will be calculated as the cross product of the first two The anisotropy directions will be automatically normalized if necessary so for example 1 1 1 is valid input it will be modified to 5774 5774 5774 For cubic materials Dir2 will be adjusted to be perpendicular to Dirl by subtracting out the component parallel to Dir1 Anisotropy Init Method to use to set up directions of anisotropy axes as a function o
5. 8http www activestate com Products ActiveTcl http purl org tcl home 15 Uncomment either the unset cpuopts line to make a generic build or else edit the set cpuopts line to an appropriate common denominator architecture and uncomment that line In a similar vein some compilers support a fast switch which usually creates an architecture specific executable The same considerations apply in this case An advanced alternative would be to define separate OOMMF platforms for each CPU subtype in your cluster At a minimum this would involve creating separate platform name files in oommf config names for each subtype and then making copies of the appropriate oommf config platforms file for each new platform The platform name files would have to be written so as to reliably detect the CPU subtype on each machine See Managing OOMMF platform names Sec 2 3 5 for details on creating platform name files 2 4 2 Microsoft Windows Options This section lists installation options for Microsoft Windows Using Microsoft Visual C If you are building OOMMEF software from source us ing the Microsoft Visual C command line compiler cl exe it is necessary to run vevars32 bat to set up the path and some environment variables This file is distributed as part of Visual C You may want to set up your system so this batch file gets run automatically when you boot the system or open a command prompt See your comp
6. omfsh exe invalid argument This cryptic message most likely means that the pre compiled OOMMF binaries which were downloaded are for a different version of Tcl Tk than is installed on your system Download OOMMEF again taking care this time to retrieve the binaries that match the release of Tcl Tk you have installed 231 8 10 11 When first starting oommf tc1 there is an error Error in startup script Neither Omf_export nor Omf_export_list set in The file oommf pkg net omfExport tcl may be missing from your OOMMF installa tion If necessary download and install OOMMF again When launching oommf tcl on Unix systems there is an error of the form error while loading shared library libtk8 4 so cannot open shared object file No such file or directory This typically happens because the libtk so and or libtcl so files are installed in a directory not included in the ld so runtime linker loader search path One way to fix this is to add that directory say usr local lib to the LD_LIBRARY_PATH environment variable For example include export LD_LIBRARY_PATH LD_LIBRARY_PATH usr local lib in your bashrc file bash shell users or setenv LD_LIBRARY_PATH LD_LIBRARY_PATH usr local lib in your cshrc file csh or tesh shell users Another option is to modify the ld so cache see the ld so and ldconfig man pages for details When launching multiple OOMMF applications on Windows 9X there is an
7. and the second is the angle from the z axis in degrees of the projection onto the xy plane Vortex Fits an idealized vortex about the center of the sample avfFile filename The second parameter specifies an OVF VIO i e any vector field file to use to initialize the magnetization The grid in the input file will be scaled as necessary to fit the grid in the current simulation The file must be accessible to the intended solver application 17 3 5 Experiment parameters The following records specify the applied field schedule e Field Range Specifies a range of applied fields that are stepped though in a linear manner The parameter list should be 7 numbers followed by optional control point stopping criteria specifications The 7 required fields are the begin field Bx By Bz in Tesla the end field Bx By Bz in Tesla and an integer number of steps intervals to 213 take between the begin and end fields inclusive Use as many Field Range records as necessary they will be stepped through in order of appearance If the step count is 0 then the end field is ignored and only the begin field is applied If the step count is larger than 0 and the begin field is the same as the last field from the previous range then the begin field is not repeated The optional control point specs determine the conditions that cause the applied field to be stepped or more precisely end the simulation of the magnetization evolution for
8. compiler usr bin g t Version string g GCC 4 1 2 20080704 Red Hat 4 1 2 51 Shell details tclsh running usr bin tclsh8 4 gt Version 8 4 13 64 bit threaded http www info zip org pub infozip UnZip html tclsh OOMMF usr bin tclsh8 4 gt Version 8 4 13 64 bit threaded filtersh usr local oommf app omfsh linux x86_64 filtersh gt Version 8 4 13 64 bit threaded tclConfig sh usr 1ib64 tclConfig sh gt Version 8 4 13 wish OOMMF usr bin wish8 4 gt Version 8 4 13 Tk 8 4 13 64 bit threaded tkConfig sh usr 1ib64 tkConfig sh gt Tk Version 8 4 13 OOMMF threads Yes Default thread count 4 NUMA support No Temp file directory tmp If oommf tcl platform doesn t print a summary similar to the above it should in stead print an error message describing why it can t For example if your Tcl installation is older than release 7 5 the error message will report that fact Follow the instructions pro vided and repeat until oommf tcl platform successfully prints a summary of the platform configuration information The first line of the example summary reports that OOMMF recognizes the platform by the name linux x86_64 OOMME software recognizes many of the more popular computing platforms and assigns each a platform name The platform name is used by OOMMF in index and configuration files and to name directories so that a single OOMMF installation can support multiple platform
9. dt a dM MIM x He Mx FE 3 where y is the Gilbert gyromagnetic ratio is mathematically equivalent to the Landau Lifshitz form under the relation y 1 a 7 The Specify block has the form 66 Specify Oxs_EulerEvolve name alpha a gamma LL 7 gamma_G y do_precess precess min timestep minimum_stepsize max_timestep mazimum_stepsize fixed_spins atlas_spec region region start_ dm Am error rate rate absolute_step error abs_error relative_step_error rel_error step_headroom headroom All the entries have default values but the ones most commonly adjusted are listed first The options alpha gamma_LL and gamma_G are as in the Landau Lifshitz Gilbert ODE 2 3 where the units on Y and y are m A s and a is dimensionless At most one of y and y should be specified If neither is specified then the default is y 2 211 x 10 Because of the absolute value convention adopted on and y in 2 3 the sign given to the value of gamma_LL or gamma_G in the Specify block is irrelevant The default value for a is 0 5 which is large compared to experimental values but allows simulations to converge to equilibria in a reasonable time However for accurate dynamic studies it is important to assign an appropriate value to a The do_precess value should be either 1 or 0 and determines whether or not the precession term in the Landau Lifshitz ODE i e the first term on the righthand side in 2 is u
10. pixel opaque If the opaque value is 1 then the pixel is drawn in a solid manner concealing any arrows which are drawn under it If opaque is 0 then the pixel is drawn only partially filled in so objects beneath it can still be discerned misc background Specify the background color misc drawboundary If 1 then draw the bounding polygon if any as specified in the input vector field file misc boundarycolor String specifying the bounding polygon color if drawn misc boundarywidth Width of the bounding polygon in pixels misc margin The size of the border margin in pixels misc defaultwindowwidth misc defaultwindowheight Width and height of initial dis play viewport in pixels misc width misc height Width and height of displayed area This will be less than the viewport dimensions if scrollbars are present These values are ignored during mm Disp initialization but are written out by the File Write config command as a convenience for the avf2ppm Sec 16 4 command line utility misc rotation Counterclockwise rotation in degrees either 0 90 180 or 270 misc zoom Scaling factor for the display This is the same value as shown in the zoom box in the mmDisp control bar and corresponds roughly to the number of pixels per vector in the original fully sampled vector field If set to zero then the scaling is set so the image including margins just fits inside the viewport dimensions 143 misc datascale Scale f
11. value pairs The default labels are e basename e scalar_output_format e scalar_field_output_format e scalar_field_output_meshtype e vector_field_output_format e vector_field_output_meshtype The basename value is used as a prefix for output filename construction by the data output routines If basename is not specified then the default value is taken from the filename of the input MIF file The scalar_output_format value is a C style printf string specifying the output format for DataTable output This is optional with de fault value 17g The values associated with scalar_field_output_format and vector_field_output_format should be two element lists that specify the style and precision for scalar and vector field output sent to mmDisp Sec 13 and mmArchive Sec 14 The first element in the list should be one of binary or text specifying 202 the output style If binary output is selected then the second element specifying pre cision should be either 4 or 8 denoting component binary output length in bytes For text output the second element should be a C style printf string like that used by scalar_output_format The default value for both scalar_field_output_format and vector _field_output_format is binary 8 The values for scalar_field_output_meshtype and vector_field_output_meshtype should be either rectangular default or ir regular specifying the grid type for the corresponding field output f
12. 2A uM In the first case the A block specifies A values on a region by region basis where the regions are labels declared by atlas_spec This allows for specification of A both inside a given region e g A and along interfaces between regions e g Aj By symmetry if A is specified then the same value is automatically assigned to Aji as well The default_A value is applied to any otherwise unassigned Ajj In the second case one specifies the magnetostatic exchange length instead of A but the interpretation is otherwise analogous Although one may specify A resp lex for any pair of regions i and J it is only required and only active if the region pair are in contact If long range exchange interaction is required use Oxs_TwoSurfaceExchange Examples grill mif spinvalve mif tclshapes mif Oxs_UniformExchange Similar to Oxs_Exchange6Ngbr except the exchange con stant A or exchange length lex is uniform across all space The Specify block is 54 very simple consisting of either the label A with the desired exchange coefficient value in J m or the label lex with the desired magnetostatic exchange length in meters Since A resp lex is not spatially varying it is initialized with a simple constant as opposed to a scalar field object Examples sample mif cgtest mif stdprob3 mif Oxs_ExchangePtwise The exchange coefficient A is specified on a point by point or cell by cell basis as opposed to the
13. Comp Appl Math 6 19 26 1980 J R Dormand and P J Prince A reconsideration of some embedded Runge Kutta formulae J Comp Appl Math 15 203 211 1986 J Fidler and T Schrefl Micromagnetic modelling the current state of the art J Phys D Appl Phys 33 R135 R156 2000 T L Gilbert A Lagrangian formulation of the gyromagnetic equation of the magne tization field Phys Rev 100 1243 1955 P R Gillette and K Oshima Magnetization reversal by rotation J Appl Phys 29 529 531 1958 L Landau and E Lifshitz On the theory of the dispersion of magnetic permeability in ferromagnetic bodies Physik Z Sowjetunion 8 153 169 1935 R D McMichael and M J Donahue Head to head domain wall structures in thin magnetic strips IEEE Trans Mag 33 4167 4169 1997 L N el Some theoretical aspects of rock magnetism Adv Phys 4 191 242 1955 A J Newell W Williams and D J Dunlop A generalization of the demagnetizing tensor for nonuniform magnetization J Geophysical Research Solid Earth 98 9551 9555 1993 D G Porter and M J Donahue Generalization of a two dimensional micromagnetic model to non uniform thickness Journal of Applied Physics 89 7257 7259 2001 234 17 18 19 20 21 M R Scheinfein J Unguris J L Blue K J Coakley D T Pierce and R J Celotta Micromagnetics of do
14. FastPipe Algorithm suitable for simulations that have infinite extent in the z direction This is a 2D version of the 3dSlab algorithm None No demagnetization Fastest but least accurate method All of these algorithms except FastPipe and None require that the Part Thickness cf the Part Geometry section be set Fast Fourier Transform FFT techniques are used to accelerate the calculations 17 3 3 Part geometry e Part Width Nominal part width z dimension in meters Should be an integral multiple of Cell Size 211 Part Height Nominal part height y dimension in meters Should be an integral multiple of Cell Size Part Thickness Part thickness z dimension in meters Required for all demag types except FastPipe and None Cell Size In plane xy plane edge dimension of base calculation cell This cell is a rectangular brick with square in plane cross section and thickness given by Part Thick ness N B Part Width and Part Height should be integral multiples of Cell Size Part Width and Part Height will be automatically adjusted slightly up to 0 01 to meet this condition affecting a small change to the problem but if the required adjustment is too large then the problem specification is considered to be invalid and the solver will signal an error Part Shape Optional Part shape in the xy plane must be one of the following Rectangle The sample fills the area specified by Part Width and Part Height D
15. Oxs_RandomVectorField 95 Oxs_RectangularMesh 52 Oxs_RungeKuttaEvolve 69 Oxs_ScriptAtlas 50 Oxs_ScriptOrientScalarField 88 Oxs_ScriptOrient VectorField 96 Oxs_ScriptScalarField 84 Oxs_ScriptUZeeman 60 Oxs_Script VectorField 93 Oxs_SimpleDemag 59 Oxs_SpinXferEvolve 71 Oxs_StageZeeman 63 Oxs_TimeDriver 77 Oxs_TransformZeeman 61 Oxs_TwoSurfaceExchange 55 Oxs_UniaxialAnisotropy 53 Oxs_UniformExchange 54 Oxs_UniformScalarField 82 Oxs_UniformVectorField 92 Oxs_U Zeeman 59 Oxs_VecMagScalarField 87 Oxs_Ext referencing MIF 188 parallelization 7 11 13 36 41 43 44 see also NUMA part geometry 211 PID s 174 175 platform 230 configuration 5 MacOSX configuration 20 names 6 13 15 Unix configuration 15 16 executable Tcl scripts 31 PostScript to printer 130 136 X server 149 Windows Borland C 16 configuration 8 16 20 Cygwin environment 7 16 desktop shortcut 20 Digital Mars C 18 dummy user ID 33 169 175 176 file extension associations 19 31 file path separator 8 hosts file 8 Microsoft Visual C 16 network socket bug 39 44 113 no Tcl configuration file 7 setting environment variables 19 wildcard expansion 158 162 platforms 4 ports 170 precession 210 processes host server 170 killing 169 random numbers 216 record identifier 209 reporting bugs 230 236 requirement 240 application version see launch version re quirement C compiler 4 d
16. Sec 14 processes The vector field outputs include pointwise magnetization various total and partial mag netic fields and torques Unlike the scalar outputs the vector field outputs are listed in dividually in the Output scroll box Allowed destinations for vector field output are run ning instances of mmDisp Sec 13 and mmArchive Sec 14 Caution is advised when scheduling vector field output especially with large problems because the output may run many megabytes 37 Controls The File menu button holds five entries Load Show Console Close Interface Clear Schedule and Exit Oxsii File Load launches a dialog box that allows the user to select an input MIF problem description file File Show Console brings up a Tcl shell console running off the Oxsii interface Tcl interpreter This console is intended primary for debugging purposes In particular output from MIF Report commands Sec 17 1 2 may be viewed here File Close Interface will remove the interface window from the display but leaves the solver running This effect may also be obtained by deselecting the Oxsii interface button in the Threads list in mmLaunch File Clear Schedule will disable all currently active output schedules exactly as if the user clicked through the interactive schedule interface one output and destination at a time and disabled each schedule enabling checkbutton The final entry File Exit Oxsii terminates the Oxsii solver and closes the int
17. The first convention is that the initialization string be structured as a Tcl list with an even number of elements with consecutive elements consisting of a label value pairs In the 187 above example the initialization string consists of two label value pairs alpha 0 5 and start_dm 0 01 The first specifies that the damping parameter a in the Landau Lifshitz ODE is 0 5 The second specifies the initial step size for the integration routine Interested parties should refer to a Tcl programming reference e g 20 for details on forming a proper Tcl list but in short the items are separated by whitespace and grouped by double quotes or curly braces and Opening braces and quotes must be whitespace separated from the preceding text Grouping characters are removed during parsing In this example the list as a whole is set off with curly braces and individual elements are white space delimited Generally the ordering of the label value pairs in the initialization string is irrelevant i e start_dm 0 01 could equivalently precede alpha 0 5 Sometimes the value portion of a label value pair will itself be a list as in this next example Specify Oxs_BoxAtlas myatlas Specify Oxs_RectangularMesh mymesh cellsize 5e 9 5e 9 5e 9 atlas Oxs_BoxAtlas myatlas Here the value associated with cellsize is a list of 3 elements which declare the sampling rate along each of the coordinate a
18. argument list is the complete list in the aforementioned order The units for the time arguments are seconds The return value from the script should be a 6 tuple of numbers Hx Hy Hz dHx dHy dHz representing the applied field and the time derivative of the applied field The field as a function of time must be differentiable for the duration of each stage Discontinuities are permitted between stages If a time evolver is 60 being used then it is very important that the time derivative values are correct otherwise the evolver will not function properly This usual symptom of this problem is a collapse in the time evolution step size The field and its time derivative are multiplied by the multiplier value before use The final field value should be in A m if the Tcl script returns the field in T then a multiplier value of 1 j9 approx 795774 72 should be applied to convert the Tcl result into A m The default value for multiplier is 1 The stage_count parameter informs the Oxs_Driver Sec 7 3 5 as to how many stages the Oxs_ScriptUZeeman object wants A value of 0 the default indicates that the object is prepared for any range of stages The stage_count value given here must be compatible with the stage _count setting in the driver Specify block q v The following example produces a sinusoidally varying field of frequency 1 GHz and amplitude 800 A m directed along the z axis Specify Oxs_ScriptUZeeman script_args tota
19. e LEFT same as menu selection View Rotate ccw e RIGHT same as menu selection View Rotate cw When the active subwindow is any of the control bar s value entry windows arrow subsample size data scale or zoom the following key combinations are active e ESC undo uncommitted value displayed in red e RETURN commit entered value When the active subwindow is in any of the control bar s sliders arrow subsample data scale or slice the following key combinations are active e LEFT slide left decrease value e RIGHT slide right increase value e ESC undo uncommitted value displayed in red e RETURN commit current value When any of the separate dialog windows are displayed e g the File Open or Options Configure dialogs the shortcut CTRL control period will raise and transfer keyboard focus back to the root mmDisp window 141 Configuration files The various initial display parameters e g window size orientation colormap are set by configuration files The default configuration file oommf app mmdisp scripts mmdisp config is read first followed by the local customization file oommf app mmdisp scripts local mmdisp config if it exists Lastly any files passed as config options on the command line are input The files must be valid Tcl scripts the main purpose of which is to set elements of the plot_config and print_config arrays as illustrated in the default con
20. height misc crop misc zoom misc rotation misc datascale misc relcenterpt 0 viewaxis viewaxis xarrowspan viewaxis xpixelspan viewaxis yarrowspan viewaxis ypixelspan viewaxis Zarrowspan viewaxis zpixelspan FFFFFF 1 1 000000 front 0 FFFFFF 10 640 480 0 5 0 5 Figure 5 Contents of default configuration file avf2ppm config 164 config file User configuration file that specifies image display parameters This file is discussed in detail below f Force overwriting of existing output files By default if avf2ps tries to create a file say foo ps that already exists it generates instead a new name of the form foo ps 000 or foo ps 001 or foo ps 999 that doesn t exist and writes to that instead The f flag disallows alternate filename generation and overwrites foo ps instead filter program Post processing application to run on each avf2ps output file May be a pipeline of several programs ipat pattern Specify input files using a pattern with glob style wildcards Mostly useful in DOS opatexp regexp Specify the regular expression applied to input filenames to determine portion to be replaced in generation of output filenames The default regular expression is A IPT sr irs l9 opatsub sub The string with which to replace the portion of input filenames matched by the opatexp regexp during output filename generation The default is eps v level Verbosity
21. i e 50 1 The second optional parameter exclude_0_Ms is a convenience operator if novacuum is 1 then the select field is reset so that it is the zero vector at all cells in the simulation where the saturation magnetization is zero This is especially useful when you want to compute the average magnetization of a shaped part The change to the select field is made before the denominator in 6 is computed so setting exclude_O_Ms to 1 is equivalent to defining the select field as being zero where M is zero in the first place The default value for this parameter is 0 which results in the select field being used exactly as defined The user_scaling parameter default value 1 0 allows the user to define a constant factor that is multiplied against the result of 6 This can be used for example in conjuction with the units parameter to implement unit conversion The units value is an arbitrary string for example A m that is placed in the DataTable output If units is not set then the units string is copied from the units for the source field 195 The following is a simple example showing two user outputs based off the demagnetization field Specify Oxs_BoxAtlas atlas subst xrange 0 cube_edge yrange 0 cube_edge zrange 0 cube_edge Specify Oxs_BoxAtlas octant subst xrange 0 expr cube_edge 2 yrange 0 expr cube_edge 2 zrange 0 expr cube_edge 2 Specify Oxs_AtlasVectorField octant_fie
22. in the Material Parameters section Thickness is determined by the relative darkness of the pixels in the bitmap Black pixels are given full nominal thickness specified by the Part Thickness parameter above and gray pixels are linearly mapped to a thickness between the nominal thickness and 0 In general bitmap pixel values are converted to a thickness relative to the nominal thickness by the formula 1 R G B 3M where R G and B are the magnitudes of the red green and blue components respectively and M is the maximum allowed component magnitude For example black has R G B 0 so the relative thickness is 1 and white has R G B M so the relative thickness is 0 The code does not perform a complete 3D evaluation of thickness effects Instead the approximation discussed in 16 is implemented 17 3 4 Initial magnetization e Init Mag Name of routine to use to initialize the simulation magnetization directions as a function of position and routine parameters if any Optional with default Random The list of routines is long and it is easy to add new ones See the file oommf app mmsolve maginit cc for details A few of the more useful routines are Random Random directions on the unit sphere This is somewhat like a quenched thermal demagnetized state Uniform 0 Uniform magnetization in the direction indicated by the two additional parame ters 0 and where the first is the angle from the z axis in degrees
23. informational message level with 0 generating only error messages and larger numbers generating additional information The level value is an integer defaulting to 1 infile List of input files to process The file specification options ipat opatexp and opatsub are interpreted in the same manner as for the avf2ppm application If you have command line PostScript processing filter programs e g ghostscript then you can use the filter option to pipe the output of avf2ps through that filter before it is written to the output file specified by the opat expressions If the processing changes the format of the file e g from PostScript to PDF then you will likely want to specify a opatsub different from the default Here is an example that processes all files with the ovf extension sending the output through ps2pdf part of the ghostscript package before saving the results in files with the extension pdf tclsh oommf tcl avf2ps ipat ovf opatsub pdf filter ps2pdf On Unix either drop the ipat flag or use quotes to protect the input file specification string from expansion by the shell as in ipat ovf 165 Configuration files The details of the conversion process are specified by plain text configuration files in the same format as the mmDisp configuration file Sec 13 page 142 The arrays plot_config and print_config hold the configurable parameters The de fault values for the
24. script in order to completely control which slave applications are launched and how they are launched When batchslave is to be launched the spawn command might be exec tclsh oommf tcl batchslave tk 0 server host server port slaveid passwd batchsolve tcl restart 1 amp The Tcl command exec is used to launch subprocesses When the last argument to exec is amp the subprocess runs in the background The rest of the spawn command should look familiar as the command line syntax for launching batchslave The example spawn command above cannot be completely provided by the task script however because parts of it are only known by batchmaster Because of this the task script should define the spawn command using percent variables which are substituted by batchmaster Continuing the example the task script provides the spawn command exec tclsh oommf batchslave tk 0 connect_info batchsolve tcl restart 1 118 batchmaster replaces tclsh with the path to tclsh and Zoommf with the path to the OOMMEF bootstrap application It also replaces connect_info with the five arguments from through password that provide batchslave the hostname and port where batchmaster is waiting for it to report to and the ID and password it should pass back In this example the task script instructs batchslave to source the file batchsolve tcl and pass it the arguments restart 1 Finally batchmaster always appends the argument amp to t
25. then the step size is reduced and the integration procedure is repeated If the step is accepted 112 then the error between the predicted and final M is used to adjust the size of the next step No fixed ratio between the previous and current time step is assumed A fourth order Runge Kutta solver is used to prime the predictor corrector solver and is used as a backup in case the predictor corrector fails to find a valid step The Runge Kutta solver is not selectable as the primary solver at runtime but may be so selected at compile time by defining the RUNGE_KUTTA_ODE macro See the file oommf app mmsolve grid cc for all details of the integration procedure For a given applied field the integration continues until a control point cf Experiment parameters Sec 17 3 5 is reached A control point event may be raised by the ODE iteration count elapsed simulation time or by the maximum value of M x Hggl M dropping below a specified control point torque value implying an equilibrium state has been reached Depending on the problem size mmSolve2D can require a good deal of working memory The exact amount depends on a number of factors but a reasonable estimate is 5 MB 1500 bytes per cell For example a 1 um x 1 um part discretized with 5 nm cells will require approximately 62 MB Known Bugs mmSolve2D requires the damping coefficient to be non zero See the MIF 1 1 documenta tion Sec 17 3 for details on specifying the dampi
26. 15 which is included in the OOMMF release but the help documentation files are standard HTML so any web browser for example Netscape Navigator or Microsoft Internet Explorer may be used instead Complete instructions are in the file config options tcl 2 3 3 Optimization In the interest of successful compilation of a usable software package out of the box the default configuration for OOMMF does not attempt to achieve much in terms of optimization However in each platform s configuration file for example config platforms wintel tcl there are alternative values for the configuration s optimization flags available as comments If you are familiar with your compiler s command line options you may experiment with other choices as well You can edit the platform configuration file to replace the default selection with another choice that provides better computing performance For example in config platforms wintel tcl alternative optimization flags for the MSVC compiler are defined with the line config SetValue program_compiler_ct _option_opt format G5 0x The extensible solver Oxs can be compiled with debugging support for extensive run time code checks This will significantly reduce computation performance In the standard OOMMF distributions these checks should be disabled You may verify this by checking that the following line appears in the file config options tcl Oc_Option Add Platform cflags def
27. File Refresh or the Refresh button causes mmHelp to reload and redisplay the current page This may be useful if the display becomes corrupted or for repeatedly loading a hypertext file which is being edited When mmHelp encounters hypertext elements it does not recognize it will attempt to work around the problem However in some cases it will not be able to make sense of the hypertext and will display an error message Documentation authors should take care to use only the hypertext elements supported by mmHelp in their documentation files Users should never see such an error message mmHelp displays error messages in one of two ways within the display window or in a separate window Errors reported in the display window replace the display of the page of hypertext They usually indicate that the hypertext page could not be retrieved or that its contents are not hypertext File permission errors are also reported in this way Errors reported in a separate window are usually due to a formatting error within the page of hypertext Selecting the Continue button of the error window instructs mmHelp to attempt to resume display of the hypertext page beyond the error Selecting Abort abandons further display The menu selection Options Font scale brings up a dialog box through which the user may select the scale of the fonts to use in the display window relative to their initial size The menu selection File Exit or the Exit button termina
28. Leaves OOMMF in the state of its distribution with pre compiled executables clean Removes the files removed by the objclean target Also removes the executables and libraries created by the all target Leaves the files generated by the configure target distclean Removes the files removed by the clean target Also removes all files and di rectories generated by configure target Leaves only the files which are part of the source code distribution 177 maintainer clean Remove all files which can possibly be generated from other files The generation might require specialized developer tools This target is not recommended for end users but may be helpful for developers help Print a summary of the standard targets 178 17 Problem Specification File Formats MIF Micromagnetic simulations are specified to the OOMMF solvers using the OOMMF Micro magnetic Input Format MIF There are four distinct versions of this format The oldest format version 1 1 is used by the mmSolve 2D solvers mmSolve2D Sec 10 1 and batch solve Sec 10 2 1 and the mmProbEd Sec 8 problem editor The MIF 2 1 and MIF 2 2 formats are the powerful native format used by the Oxs 3D solvers Sec 7 The MIF 1 2 format is a minor modification to the 1 1 format which can be used as a simple but restricted interface to the Oxs solvers In all cases values are specified in SI units A command line utility mifconvert Sec 16 11 is provided to aid in converting
29. MIF 1 1 files to the MIF 2 1 format For all versions it is recommended that MIF files be given names ending with the mif file extension 17 1 MIF 2 1 The MIF 2 x format was introduced with the Oxs 3D solver Sec 7 It is not backwards compatible with the MIF 1 x formats however a conversion utility mifconvert Sec 16 11 is available to aid in converting MIF 1 x files to the MIF 2 1 format 17 1 1 MIF 2 1 File Overview The first line of a MIF file must be of the form MIF x y where x y represents the format revision number here 2 1 Unlike MIF 1 1 files the structure of MIF 2 1 files are governed by the requirement that they be valid Tcl scripts albeit with a handful of extensions These files are evaluated inside a Tcl interpreter which may be a safe interpreter i e one in which disk and other system access is disabled Refer to the documentation of the Tcl interp command for details on safe interpreters The security level is controlled by the MIFinterp option in the options tcl customization file Sec 2 3 2 The default setting is Oc_Option Add Oxs MIFinterp safety custom which enables all the Tcl interpreter extensions described in MIF 2 1 Extension Commands Sec 17 1 2 below but otherwise provides a standard Tcl safe interpreter The keyword custom above may be replaced with either safe or unsafe The safe selection is similar to custom except that the ReadFile and RGlob extensions are not provided th
30. MaskField m vx vy vz return list expr m vx expr m vy expr m vz F Specify Oxs_ScriptVectorField script MaskField script_args scalars vectors scalar_fields mask vector_fields vfield Of course the Oxs_ScriptVectorField approach is easily generalized to much more complicated and arbitrary combinations of scalar and vector fields Example rotatecenterstage mif Oxs_ImageVectorField This class creates a vector field using an image The Specify block has the form Specify Oxs_ImageVectorField name image pic multiplier mult vx_multiplier smult vy multiplier ymult vz multiplier zmult vx_offset zoff vy_offset yoff vz_offset zoff norm norm_magnitude viewplane view atlas atlas_spec 100 xrange rmin zmar yrange ymin ymaz zrange zmin zmax exterior ext_flag The image is interpreted as a three color map yielding a vector field where each x y z component is determined by the red green and blue color components respectively The viewplane atlas xrange yrange zrange and exterior are treated the same as for the Oxs_ImageScalarField class q v Examples NONE 7 3 7 MIF Support Classes Oxs_LabelValue A convenience object that holds label value pairs Oxs_LabelValue objects may be referenced via the standard attributes field in other Specify blocks as in this example Specify Oxs_LabelValue probdata alpha 0 5 start_dm 0 01 Specify Oxs_Euler
31. NDEBUG To enable these checks either comment remove this line or else add to the config local options tcl file a cflags option line without def NDEBUG such as Oc_Option Add Platform cflags warn 1 The config local options tcl file may be created if it does not already exist 2 3 4 Parallelization The OOMMF Oxs 3D solvers oxsii amd boxsi can be built thread enabled to allow parallel processing on multi processor multi core machines In order to build and run a parallel version of OOMMF you must have a thread enabled version of Tcl Most standard binary releases of Tcl today are thread enabled so OOMMF releases that include pre built 11 executables are built thread enabled If you build OOMMF from source then by default OOMMF will be built thread enabled if your Tcl is thread enabled As explained earlier you can check thread build status with the tclsh oommf tcl platform command If you want to force a non threaded build of OOMMF then edit the config platforms file for your platform In the section labeled LOCAL CONFIGURATION you will find a line that looks like config SetValue oommf_threads 0 Uncomment this line i e remove the leading character to force a non threaded build Then run tclsh oommf tcl pimake distclean tclsh oommf tcl pimake from the OOMMF root directory to create a fresh build You can use the tclsh oommf tcl platform command to see the default number of compute t
32. OOMMEF there is only one checkbutton localhost Future releases of mmLaunch will be able to connect to remote 32 hosts as well If there is no host service directory running on the localhost when mm Launch is launched mmLaunch will start one In that circumstance there may be some delay before the localhost check button appears Toggling the localhost checkbutton toggles the display of an interface to the host service directory The host service directory interface consists of a row of checkbuttons one for each account service directory registered with the host service directory Each checkbutton is labeled with the user ID of the corresponding account service directory For most users there will be only one checkbutton labeled with the user s own account ID except on Windows 9X where the dummy account ID oommf may be displayed instead If there is no account service directory running for the account under which mmLaunch was launched mmLaunch will start one In that circumstance there may be some delay before the account checkbutton appears Toggling an account checkbutton toggles the display of an interface to the corresponding account service directory The account service directory interface consists of two columns The Programs column contains buttons labeled with the names of OOMMF applications that may be launched under the account managed by this account service directory Clicking on one of these buttons launches the corre
33. Options Arrow Subsample 2 Data Scale A m 485000 f Overview The application mmDisp displays two dimensional spatial distributions of three dimensional vectors i e vector fields It can load vector fields from files in a variety of formats or it can accept vector field data from a client application typically a running solver mmDisp offers a rich interface for controlling the display of vector field data and can also save the data to a file and produce Postscript print output Launching mmDisp may be started either by selecting the mmDisp button on mmLaunch or from the command line via tclsh oommf tcl mmDisp standard options config file net lt 0 1 gt filename config file User configuration file that specifies default display parameters This file is discussed in detail below net lt 0 1 gt Disable or enable a server which allows the data displayed by mmDisp to be updated by another application By default the server is enabled When the server is disabled mmDisp may only input data from a file 134 If a filename is supplied on the command line mmDisp takes it to be the name of a file containing vector field data for display That file will be opened on startup Inputs Input to mmDisp may come from either a file or from a client application typically a running solver in any of the vector field formats described in Sec 19 Other file formats can also be supporte
34. Schedule command for the monitor destination delivers output to the monitoring mmGraph every 5 iterations of the solver The last Destination command tags an arbitrary mmArchive application which is used for file storage of DataTable results at the end of each stage and snapshots of the magnetization and total field at the end of every third stage Note that double quotes enclose the Oxs_EulerEvolve Total field output name Without the quotes the Schedule command would see five arguments Oxs_EulerEvolve Total field archive Stage and 3 17 1 3 Specify Conventions The Specify blocks in the input MIF file determine the collection of Oxs_Ext objects defin ing the Oxs simulation As explained above the Specify command takes two arguments the name of the Oxs_Ext object to create and an initialization string The format of the initialization string can be arbitrary as determined by the author of the Oxs_Ext class This section presents a number of recommended conventions which Oxs_Ext class authors are en couraged to follow Any Oxs_Ext classes that don t follow these conventions should make that fact explicitly clear in their documentation Details on the standard Oxs_Ext classes included with OOMMF can be found in the Oxs documentation Sec 7 17 1 3 1 Initialization string format Consider again the simple Specify block pre sented above Specify Oxs_EulerEvolve foo alpha 0 5 start_dm 0 01
35. The title bar of running OOMMF applications typically displays the application OID which are used by OOMMF applications to identify one another These ID s start at 0 and are incremented each time a newly launched application registers with the account server The OID s are independent of the operating system PID s The PID is needed to obtain informa tion e g resource use about a running process using system utilities The PID may also be needed to invoke the operating system kill facility to terminate a rogue OOMMF appli cation The pidinfo application can be used to correspond OID s or OOMMF application names to PID s for such purposes 16 14 Process Nicknames nickname The nickname command associates nicknames to running instances of OOMMF applica tions These names are used by the MIF 2 x Destination command Sec 17 1 2 175 Launching The nickname command line is tclsh oommf tcl nickname standard options account name hostport port pid timeout secs oid nickname where account name Specify the account name The default is the same used by mmLaunch Sec 6 the current user login name except on Windows 9X where the dummy account ID oommf may be used instead hostport port Use the host server listening on port Default is set by the Net_Host port setting in oommf config options tcl or by the environment variable OOMMF_HOSTPORT which if set overrides the former The stand
36. a first pass to reveal the column headers specific column selections may then be made in a second separate invocation If no options or columns are specified then the help message is displayed 16 13 OOMME and Process ID Information pidinfo The pidinfo command returns the mapping of OOMMF ID s OID s to system process ID s PID s 174 Launching The pidinfo command line is tclsh oommf tcl pidinfo standard options account name hostport port names noheader ports timeout secs v oid where account name Specify the account name The default is the same used by mmLaunch Sec 6 the current user login name except on Windows 9X where the dummy account ID oommf may be used instead hostport port Use the host server listening on port Default is set by the Net_Host port setting in oommf config options tcl or by the environment variable OOMMF_HOSTPORT which if set overrides the former The standard setting is 15136 names Display application nicknames which are used by the MIF 2 1 Destination com mand Sec 17 1 2 noheader Don t print column headers ports Display active server ports for each application timeout secs Maximum time to wait for response from servers in seconds Default is five seconds v Display information about the host and account servers oid List of OOMMF ID s to display information about Default is all current applica tions
37. a pattern with glob style wildcards Especially useful in DOS Files must meet the infile requirements see below normalize lt 0 1 gt If 1 then the default averaged output values vz vy and v are divided by the maximum magnitude that would occur if all the vectors in the averaging man ifold are aligned In particular the maximum magnitude of the output vector is 1 This option should be used carefully because the normalization is done independently for each output row For normalize 0 the default averaged output values are in file units numfmt fmt C style output format for numeric data in the body of the output table Default value is A 20 15g onefile outfile Generally a avf2odt writes its output to a collection of files with names generated using the opatexp and opatsub specifications This option overrides that 156 behavior and sends all output to one place If outfile is then the output is sent to standard output otherwise outfile is the name of the output file opatexp regexp Specify the regular expression applied to input filenames to determine portion to be replaced in generation of output filenames The default regular expression is CN der ele oS opatsub sub The string with which to replace the portion of input filenames matched by the opatexp regexp during output filename generation The default is odt region xmin ymin zmin xmax ymax zmax Axes parallel rectangular box den
38. and SolverTaskCleanup procs may be redefined as well At the start of each task SolverTaskInit is called by BatchTaskRun in batchsolve tcl after each iteration BatchTaskIterationCallback is executed at each control point BatchTaskRelaxCallback is run and at the end of each task SolverTaskCleanup is called SolverTaskInit and SolverTaskCleanup are passed the arguments that were passed to BatchTaskRun A simple SolverTaskInit proc could be proc SolverTaskInit args global mif basename outtextfile set A lindex args 0 set outbasename basename A A mif SetA A mif SetOutBaseName outbasename set outtextfile open outbasename odt a 119 puts outtextfile GetTextData header Run on basename mif with A mif GetA This proc receives the exchange constant A for this task on the argument list and makes use of the global variables mif and basename Both should be initialized in the slave initialization script outside the SolverTaskInit proc It then stores the requested value of A in the mif object sets up the base filename to use for output and opens a text file to which tabular data will be appended The handle to this text file is stored in the global outtextfile which is closed by the default SolverTaskCleanup proc A corresponding task script could be TaskInfo AppendTask A 13e 12 J m BatchTaskRun 13e 12 which runs a simulation with A set to 13 x 107 J m This example is taken from the multitask tcl
39. are exactly the same 7 The data layout for data blocks using binary representation is also the same as in OVF 1 0 files except that all binary values are written in a little endian LSB order as compared to the MSB order used in the OVF 1 0 format This includes the initial check value IEEE floating point value 1234567 0 for 4 byte format corresponding to the LSB hex byte sequence 38 B4 96 49 and 123456789012345 0 for 8 byte format corresponding to the LSB hex byte sequence 40 DE 77 83 21 12 DC 42 as well as the subsequent data records In all other respects the OVF 1 0 and OVF 2 0 are the same An example OVF 2 0 file for an irregular mesh with N 2 follows Fig 12 HH HH H HH HOH HO OH FH OF OOMMF OVF 2 0 segment count 1 Begin Segment Begin Header Title Long file name or title goes here Desc Optional description line 1 Desc Optional description line 2 Desc Fundamental mesh measurement unit Treated as a label meshunit nm meshtype irregular pointcount 5 Number of nodes in mesh xmin O Corner points defining mesh bounding box in ymin O meshunit Floating point values zmin O xmax 10 ymax 5 zmax 1 226 valuedim 2 Value dimension Fundamental field value units treated as labels i e unparsed In general there should be one label for each value dimension valueunits J m 3 A m valuelabels Z
40. as Oxs_RungeKuttaEvolve and Oxs_MinDriver for controlling minimization evolvers like Oxs_CGEvolve Oxs_TimeDriver The Oxs time driver is Oxs_TimeDriver The specify block has the form Specify Oxs_TimeDriver name evolver evolver_spec mesh mesh_spec Ms scalar_field_spec mO vector_field_spec stopping_dm_dt torque_criteria stopping time time_criteria stage_iteration_limit stage_iteration_count total_iteration_limit total_tteration_count stage count number_of_stages stage_count_check test checkpoint_file restart_file_name checkpoint_interval checkpoint_minutes checkpoint_cleanup cleanup_behavior TT start_iteration iteration start_stage stage start_stage_iteration stage_iteration start_stage_start_time stage_time start_stage_elapsed time stage_elapsed_time start_last_timestep timestep normalize_aveM_output aveMflag report_max_spin_angle report The first four parameters evolver mesh Ms and m0 provide references to a time evolver a mesh a scalar field and a vector field respectively Here Ms is the pointwise saturation magnetization in A m and m0 is the initial configuration for the magneti zation unit spins i e m 1 at each point These four parameters are required The next group of 3 parameters control stage stopping criteria The stopping_dm_dt value in degrees per nanosecond specifies that a stage should be considered complete when the maximum dm dt across all spins drops below this value Similarly the
41. by setting the customization command Oc_Option Add Nb_InputFilter ovf bar foo This assumes that the program foo accepts input of the form bar on standard input and writes the translated results to standard output Outputs The vector field displayed by mmDisp may be saved to disk via the File Save As dialog box The output is in the OVF format Sec 19 1 The OVF file options may be set by selecting the appropriate radio buttons in the OVF File Options panel The Title and Desc fields may be edited before saving Enabling the Browse button allows for saving multiple files without closing the Save File dialog box The File Print dialog is used to produce a Postscript file of the current display On Unix systems the output may be sent directly to a printer by filling the Print to entry with the appropriate pipe command e g 1lpr The exact form is system dependent The other print dialog box options are described in the configuration files section below The File Write config dialog allows one to save to disk a configuration file holding the current display parameters This file can be used to affect startup display parameters or used as input to the avf2ppm Sec 16 4 and avf2ps Sec 16 5 command line utilities that convert files from the OVF format into bitmap images and PostScript printer files respectively mmDisp does not provide direct support for writing bitmap files Details of the configuration file a
42. checkpoint file is determined by the setting of checkpoint_cleanup which should be one of normal the default done_only or never Under the nor mal setting the checkpoint file is automatically deleted upon normal program ter mination either because the solver reached the end of the problem or because the user interactively terminated the problem prematurely If cleanup_behavior is set to done_only then the checkpoint file is only deleted if the problem endpoint is reached If cleanup_behavior is never then OOMMEF does not delete checkpoint file the user is responsible for deleting this file as she desires The checkpoint interval value is the time in minutes between overwrites of the checkpoint file No checkpoint file is written until checkpoint_minutes have elapsed Checkpoint writes occur between solver iterations so the actual interval time may be somewhat longer than the specified time If checkpoint_minutes is 0 then each step is saved Setting checkpoint_minutes to 1 disables checkpointing The default checkpoint interval is 15 minutes The six start_ options control the problem run start point These are intended primarily for automatic use by the restart feature The default value for each is 0 The normalize_aveM_output option is used to control the scaling and units on the average magnetization components M M and M sent as DataTable output this includes output sent to mmDataTable Sec 11 mmGraph Sec 12 and mmArc
43. client Outputs mmDataTable does not support any data output or storage facilities To save tabular data use the mmGraph Sec 12 or mmArchive Sec 14 applications Controls The Data menu holds a list of all the data names for which mmDataTable has received data Initially mmDataTable has received no data from any clients so this menu is empty As data arrives from clients the menu fills with the list of data names Each data name on the list lies next to a checkbutton When the checkbutton is toggled from off to on the corresponding data name and its value and units are displayed at the bottom of the display window When the checkbutton is toggled from on to off the corresponding data name is removed from the display window In this way the user selects from all the data received what is to be displayed Selecting the dashed rule at the top of the Data menu detaches it so the user may easily click multiple checkbuttons Displayed data values can be individually selected or deselected with a left mouse button click on the display entry Highlighting is used to indicated which data values are currently selected The Options menu also contains commands to select or deselect all displayed values The selected values can be copied into the cut and paste clipboard buffer with the CTRL c key combination or the Options Copy menu command The data value selection mechanism is also used for data value formatting control The Options Form
44. client request so if the contents of a file change between the time of the FileSource file selection and the arrival of a request from a client the new contents will be served to the client application Controls The menu selection File Exit terminates the FileSource application The Help menu pro vides the usual help facilities 106 10 The 2D Micromagnetic Solver The OOMMF 2D micromagnetic computation engine mmSolve is capable of solving prob lems defined on a two dimensional grid of square cells with three dimensional spins This solver is older less flexible and less extensible than the Oxs Sec 7 solver Users are encouraged to migrate to Oxs where possible There are two interfaces provided to mmSolve the interactive mmSolve2D Sec 10 1 interface and the command line driven batchsolve Sec 10 2 1 interface which can be used in conjunction with the OOMMF Batch System Sec 10 2 Problem definition for mmSolve is accomplished using input files in the MIF 1 1 format Sec 17 3 Please note that this format is incompatible with the newer MIF 2 x format used by the Oxs solver However the command line utility mifconvert Sec 16 11 can be used to aid conversion from the MIF 1 1 format to MIF 2 1 mmSolve will also accept files in the MIF 1 2 format Sec 17 4 format provided the CellSize record meets the restriction that the x and y dimensions are the same and that the z dimension equals the part thickness Note on Tk
45. com putation is on the raw byte stream binary mode However if text mode is selected then text mode translations e g carriage return newline newline conversion is performed before the CRC 32 computation Text mode translations usually have no effect on Unix sys tems For additional information on text mode see the Tcl documentation for fconfigure specifically translation auto If the verbosity level is 1 or greater then the length of the byte stream as processed by the CRC 32 computation is also reported 16 8 Killing OOMMEFE Processes killoommf The killoommf application terminates running OOMMF processes Launching The killoommf command line is tclsh oommf tcl killoommf standard options account name hostport port q show shownames test timeout secs oid where account name Specify the account name The default is the same used by mmLaunch Sec 6 the current user login name except on Windows 9X where the dummy account ID oommf may be used instead 169 hostport port Use the host server listening on port Default is set by the Net_Host port setting in oommf config options tcl or by the environment variable OOMMF_HOSTPORT which if set overrides the former The standard setting is 15136 q Quiet don t print informational messages show Don t kill anything just print matching targets shownames Don t kill anything just print nicknames of matchin
46. config uration to include the STL header files The dm bin sc ini file should be edited so that the first element of the INCLUDE path is PZ stlport stlport Next use set INCLUDE and set LIBRARY from the DOS command prompt to check that these environment variables are either not set or else set to values as needed by the Digital Mars compiler These variables names may be used by other applications which will conflict with values expected by dmc To unset these vari ables use the commands set INCLUDE and set LIBRARY For convenience you probably also want to put the dm bin directory into your environment PATH variable 2http www digitalmars com 18 2 Create compatible Tcl Tk import libraries The Digital Mars linker uses the same library format as the Borland linker and as in that case you will have to build compatible import libraries for the Tcl Tk libraries The free download from Digital Mars does not include a utility to create these import libraries If you have purchased the compiler from Digital Mars you can use the coff2off or implib tools for this See the documentation for details Another option is to use the Borland tools See the section above on using Borland C for details 3 Edit oommf config platforms wintel tcl You will need to uncomment the entry for the dmc compiler and comment out the other compiler selections The comment character is The configuration fi
47. dependence If a problem is loaded that uses a bitmap mask file Sec 17 3 3 and if that mask file is not in the PPM P3 text format then mmSolve2D will launch any2ppm Sec 16 1 to convert it into the PPM P3 format Since any2ppm requires Tk at the time the mask file is read a valid display must be available See the any2ppm documentation for details 10 1 The 2D Micromagnetic Interactive Solver mmSolve2D Status Run Solver Reset LoadProblem Run Relax Pause Field Field Interactive Fee eS Exit Outputs TotalField Magnetization DataTable Scheduled Outputs Outputs Destination Threads Schedule x TotalField x mmDataTable lt 12845 gt W Iteration every 5 Magnetization mm rchive lt 12846 gt W Equilibrium every 1 DataTable mmGraph lt 12847 gt W Interactive 107 Overview The application mmSolve2D is a micromagnetic computation engine capable of solving problems defined on two dimensional square grids of three dimensional spins Within the OOMMEF architecture see Sec 4 mmSolve2D is both a server and a client application mmSolve2D is a client of problem description server applications data table display and storage applications and vector field display and storage applications mmSolve2D is the server of a solver control service for which the only client is mmLaunch Sec 6 It is through this service that mmLaunch provides a user interface window shown above on behalf
48. directions axisl and axis2 The third anisotropy axis is computed as the vector product axis1 x axis2 The axis directions are easy axes if K1 or Ha is gt 0 or hard axes if K1 or Ha is lt 0 All may be varied cellwise across the mesh K1 or Ha is initialized with a scalar field object and the axis directions are initialized with vector field objects The axisi and axis2 directions must be mutually orthogonal and non zero at each point For each cell if K1 resp Ha is gt 0 then the computed energy will be non negative else if K1 resp Ha lt 0 then the computed energy will be non positive Examples cgtest mif sample2 mif grill mif e Exchange Energy Oxs_Exchange6Ngbr Standard 6 neighbor exchange energy The exchange energy density contribution from cell 7 is given by ao ea 1 2 53 where N is the set consisting of the 6 cells nearest to cell 7 Aj is the exchange coefficient between cells i and j in J m and Aj is the discretization step size between cell and cell j in meters The Specify block for this term has the form Specify Oxs_Exchange6Ngbr name default_A value atlas atlas_spec A region 1 region 1 Ay region 1 region 2 Aj region m region n Amn or Specify Oxs_Exchange6Ngbr name default_lex value atlas atlas_spec les region 1 region 1 lex region 1 region 2 lex region m region n letmn where lex specifies the magnetostatic exchange length in meters defined by lex
49. e automatically exit when done kill tags On termination sends requests to other applications to shutdown too The tags argument should be either a list of destination tags which are declared by Destination commands Sec 17 1 2 from the input MIF file or else the keyword all which is interpreted to mean all the destination tags nice lt 0 1 gt If enabled i e 1 then the program will drop its scheduling priority after startup The default is 0 i e to retain its original scheduling priority parameters params Sets MIF 2 Sec 17 1 file parameters The params argument should be a list with an even number of arguments corresponding to name value pairs Each name must appear in a Parameter statement Sec 17 1 2 in the input MIF file The entire name value list must be quoted so it is presented to Boxsi as a single item on the command line For example if A and Ms appeared in Parameter statements in the MIF file then an option like parameters A 13e 12 Ms 800e3 40 could be used to set A to 13e 12 and Ms to 800e3 The quoting mechanism is shell operating system specific refer to your system documentation for details pause lt 0 1 gt If enabled i e 1 then the program automatically pauses after loading the specified problem file The default is 0 i e to automatically move into Run mode once the problem is loaded restart lt 0 1 2 gt Ifthe restart option is 0 the default then the problem
50. earlier OOMMF release then files in the new distribution overwrite those of the same name already on the disk Some care may be needed in that circumstance to be sure that the resulting mix of files from an old and a new OOMMF distribution combine to create a working set of files 2 2 2 Check Your Platform Configuration After downloading and unpacking the OOMMEF software distribution all the OOMMF soft ware is contained in a subdirectory named oommf Start a command line interface a shell on Unix or the MS DOS Prompt on Microsoft Windows and change the working direc tory to the directory oommf Find the Tcl shell program installed as part of your Tcl Tk installation In this manual we call the Tcl shell program tclsh but the actual name of the executable depends on the release of Tcl Tk and your platform type Consult your Tcl Tk documentation In the root directory of the OOMMEF distribution is a file named oommf tcl It is the bootstrap application Sec 5 which is used to launch all OOMMEF software With the command line argument platform it will print a summary of your platform configuration when it is evaluated by tclsh This summary describes your platform type your C compiler and your Tcl Tk installation As an example here is the typical output on a Linux x86_64 system tclsh8 4 oommf tcl platform oommf tcl 1 2 0 4 info OOMMF release 1 2 0 4 Platform Name linux x86_64 Tcl name for OS Linux 2 6 18 274 7 1 e15 C
51. environment Sec 2 4 2 page 16 POSIX style pathnames are not always recognized by OOMMF in Cygwin This is an artifact of using a standard Windows Tcl Tk which is unaware of the Cygwin unix like view of the file system At present the only workaround is to use Windows style pathnames e g C oommf tests mytest mif I ran out of memory Are you using mmGraph Sec 12 to monitor a long running simulation All data sent to mmGraph is kept in memory by default See the mmGraph documentation for information on how to manage this problem 233 21 References N 10 11 12 13 14 15 16 A Aharoni Introduction to the Theory of Ferromagnetism Oxford New York 1996 A Aharoni Demagnetizing factors for rectangular ferromagnetic prisms J App Phys 83 3432 3434 1998 D V Berkov K Ramst ck and A Hubert Solving micromagnetic problems Towards an optimal numerical method Phys Stat Sol a 137 207 222 1993 W F Brown Jr Micromagnetics Krieger New York 1978 M J Donahue and R D McMichael Exchange energy representations in computa tional micromagnetics Physica B 233 272 278 1997 M J Donahue and D G Porter OOMMF User s Guide Version 1 0 Tech Rep NIS TIR 6376 National Institute of Standards and Technology Gaithersburg MD 1999 J R Dormand and P J Prince A family of embedded Runge Kutta formulae J
52. fields Example sample reflect mif Oxs_AffineOrientScalarField The Oxs_AffineOrientScalarField class is similar to the Oxs ScriptOrientScalarField class except that the transformation on the import position is by an affine transformation defined in terms of a 3 x 3 matrix and an offset instead of a Tcl script Although this functionality can be obtained by an appropriate Tcl script the Oxs_AffineOrientScalarField is easier to use and will run faster as the underlying transformation is performed by compiled C instead of Tcl script The Specify block has the form Specify Oxs_AffineOrientScalarField name field scalar_field_spec M matriz_entries offset off off off inverse invert_flag inverse_slack slack If F x represents the scalar field specified by the field value then the resulting trans formed scalar field is F M off Here M is a 3 x 3 matrix which may be specified by a list of 1 3 6 or 9 entries If the matrix_entries list consists of a single value then M is taken to be that value times the identity matrix i e M is a homogeneous scaling transformation If matrix_entries consists of 3 values then M is taken to be the diagonal matrix with those three values along the diagonal If matrix_entries is 6 elements long then M is assumed to be a symmetric matrix where the 6 elements specified correspond to M11 My2 M13 M22 Mo3 and M33 Finally if matrix_entries is 9 elements long then the element
53. file con taining an archive of all the OOMMF source code The second format is a zip compressed archive containing source code and pre compiled executables for Microsoft Windows Each Windows binary distribution is compatible with only a particular sequence of releases of Tcl Tk For example a Windows binary release for Tcl Tk 8 3 x is compatible with Tcl Tk 8 3 0 8 3 1 Other release formats e g pre compiled executables for Microsoft Win dows NT running on a Compaq Alpha Systems RISC based microprocessor system and or compatible with older versions of Tcl Tk may be made available upon request For the first format unpack the distribution archive using gunzip and tar gunzip c oommf12a4_20040908 tar gz tar xvf Shttp math nist gov oommf software html For the other format s you will need a utility program to unpack the zip archive This program must preserve the directory structure of the files in the archive and it must be able to generate files with names not limited to the old MSDOS 8 3 format Some very old versions of the pkzip utility do not have these properties One utility program which is known to work is UnZip Using your utility unpack the zip archive e g unzip oommf12a4_20040908_84 zip For either distribution format the unpacking sequence creates a subdirectory oommf which contains all the files and directories of the OOMMF distribution If a subdirectory named oommf already existed say from an
54. fix is already documented If not please send both the complete output from pimake and the output from oommf tcl platform to the OOMMEF developers when you e mail to ask for help 2 2 4 Installing The current OOMMF release does not support an installation procedure For now simply run the executables from the directories in which they were unpacked built 2 2 5 Using OOMME Software To start using OOMMF software run the OOMMF bootstrap application Sec 5 This may be launched from the command line interface tclsh oommf tcl If you prefer you may launch the OOMMF bootstrap application oommf tcl using what ever graphical point and click interface your operating system provides By default the OOMMEF bootstrap application will start up a copy of the OOMMF application mmLaunch Sec 6 in a new window If you publish material created with the aid of OOMMF please refer to Credits Sec 22 for citation information 2 2 6 Reporting Problems If you encounter problems when installing or using OOMMF please report them to the OOMMF developers The oommf tcl platform command has been designed in large part to help OOMMF developers debug installation problems so PLEASE be sure to include the complete output from oommf tcl platform in your report See also the section on troubleshooting Sec 20 for additional instructions 2 3 Advanced Installation The following sections provide instructions for some additional installa
55. for OOMMF users on Windows 9X systems Other platforms do not have this problem 113 10 2 OQOMME 2D Micromagnetic Solver Batch System The OOMMF Batch System OBS provides a scriptable interface to the same micromag netic solver engine used by mmSolve2D Sec 10 1 in the form of three Tcl applicatons batchmaster batchslave and batchsolve that provide support for complex job schedul ing All OBS script files are in the OOMMF distribution directory app mmsolve scripts Unlike much of the OOMMF package the OBS is meant to be driven primarily from the command line or shell batch script OBS applications are launched from the command line using the bootstrap application Sec 5 10 2 1 2D Micromagnetic Solver Batch Interface batchsolve Overview The application batchsolve provides a simple command line interface to the OOMMF 2D micromagnetic solver engine Launching The application batchsolve is launched by the command line tclsh oommf tcl batchsolve standard options end_exit lt 0 1 gt end_paused interface lt 011 gt restart lt 0 1 gt start_paused file where end_exit lt 0 1 gt Whether or not to explicitly call exit at bottom of batchsolve tcl When launched from the command line the default is to exit after solving the problem in file When sourced into another script like batchslave tcl the default is to wait for the caller script to provide further instructions interface lt 0 1 gt
56. for details 117 10 2 2 2 Task Control batchslave The application batchslave may be launched by the command line tclsh oommf tcl batchslave standard options host port id password auxscript arg host port Host and port at which to contact the master to serve id password ID and password to send to the master for identification auxscript arg The name of an optional script to source which actually performs the task the slave is assigned and any arguments it needs In normal operation the user does not launch batchslave Instead instances of batch slave are launched by batchmaster as instructed by a task script Although batchmaster may launch any slaves requested by its task script by default it launches instances of batch slave The function of batchslave is to make a connection to a master program source the auxscript and pass it the list of arguments aux_arg Then it receives commands from the master and evaluates them making use of the facilities provided by auxscript Each command is typically a long running one such as solving a complete micromagnetic problem When each command is complete the batchslave reports back to its master program asking for the next command When the master program has no more commands batchslave terminates Inside batchmaster each instance of batchslave is launched by evaluating a Tcl com mand This command is called the spawn command and it may be redefined by the task
57. gt ftype TclScript C Program Files Tcl bin wish84 exe 1 2 3 4 5 6 7 8 9 19 Note that the quotes are required as shown to protect spaces in pathnames If either assoc or ftype are incorrect view the command line help information assoc and ftype for details on making changes Adding an OOMMEF shortcut to your desktop Right mouse click on the desktop to bring up the configuration dialog and select New Shortcut Enter the command line necessary to bring up OOMMF e g tclsh84 c oommf oommf tcl Click Next gt and enter OOMMF for the shortcut name Select Finish At this point the shortcut will appear on your desktop with either the tclsh or wish icons Right mouse click on the icon and select Properties Select the ShortCut tab and bring up Change Icon Under File Name enter the OOMMF icon file e g C oommf oommf ico Click OK Back on the Shortcut tab change the Run selection to Minimized Click OK to exit the Properties dialog box Double clicking on the OOMMF icon should now bring up the OOMMF application mmLaunch 2 4 3 Mac OS X Configuration This section lists installation options for Mac OS X Building OOMMF on Mac OS X 1 Check Tcl Tk pointer to ActiveTcl 2 Check C compiler Follow the basic installation instructions in the previous section If the platform con figuration check does not find a C compiler then you will have to install one Recent releases of Mac OS Xinc
58. in ASCII are easy to import into other programs that process numerical datasets and are easy to generate so the OVF 0 0 file format is useful for exchanging vector field data between OOMMEF and non OOMMF programs Furthermore the data section of an OVF 0 0 file is consistent with the data section of an OVF 1 0 file that has been saved as an irregular mesh using text data representation This means that even though OOMMF software now writes only the OVF 1 0 format for vector field data simple interchange of vector field data with other programs is still supported 228 OOMMF irregular mesh v0 0 File sample ovf Boundary XY 0 0 0 0 1 0 0 0 1 0 2 0 0 0 Grid step x Go OOOO oO oO 01 01 01 50 99 T5 99 FPrROOrRF y 01 00 99 50 05 50 99 25 5 0 OOO OOM Oe Z 01 01 01 01 01 01 01 m_x 0 35537 0 18936 0 08112 0 03302 0 08141 0 18981 0 35652 Figure 13 m_y 93472 98191 99670 99945 99668 98182 93429 o0oo0oo0oo0o0o0o O 2 0 0 0 0 0 m_z 00000 00000 00000 00001 00001 00000 00000 Example OVF 0 0 file 229 20 Troubleshooting The OOMMF developers rely on reports from OOMMEF users to alert them to problems with the software and its documentation and to guide the selection and implementation of new features See the Credits Sec 22 for instructions on how to contact the OOMMF developers The more co
59. in a simulation by specifying a positive integer value here The more usual run completion condition is based on the stage count If a positive integer value is specified for stage_count then the run will be considered complete when the stage count reaches that value If stage_count is not specified or is given the value 0 then the effective number_of_stages value is computed by examining the length of the stopping criteria lists and also any other Oxs_Ext object that has stage length expectations such as Oxs_UZeeman The longest of these is taken to be the stage limit value Typically these lengths along with 78 stage_count if specified will all be the same and any differences indicate an error in the MIF file Oxs will automatically test this condition provided stage_count_check is set to 1 which is the default value Stage length requests of 0 or 1 are ignored in this test since those lengths are commonly used to represent sequences of arbitrary length At times a short sequence is intentionally specified that is meant to be implicitly extended to match the full simulation stage length In this case the stage count check can be disabled by setting test to 0 The checkpoint options are used to control the saving of solver state to disk these saves are used by the oxsii and boxsi restart feature The value of the checkpoint file option is the name to use for the solver state file The default is base_file name restart Cleanup of the
60. in the MIF 1 2 format provided the Cell1Size record meets the restrictions of those solvers namely the z and y dimensions must be the same and the z dimension must equal the part thickness The SolverType record if any is ignored The Oxs 3D solvers will read files in the MIF 1 2 format but support only the ConstMag and None demagnetization kernels All other DemagType records are silently converted to ConstMag The SolverType record is converted into the appropriate solver driver pair 218 18 Data Table File Format ODT Textual output from solver applications that is not of the vector field variety is output in the OOMMF Data Table ODT format This is an ASCII text file format with column information in the header and one line of data per record Any line ending in a character is joined to the succeeding line before any other processing is performed Any leading characters on the second line are removed As with the OVF format Sec 19 1 all non data lines begin with a character com ments with two characters This makes it easier to import the data into external pro grams for example plotting packages An example is shown in Fig 10 The first line of an ODT file should be the file type descriptor ODT 1 0 It is also recommended that ODT files be given names ending in the file extension odt so that ODT files may be easily identified The remaining lines of the ODT file format should be
61. left mouse button displays a red rectangle that changes size as the mouse is dragged When the left mouse button is released the vector field is rescaled so that the portion of the display window within the red rectangle expands until it reaches the edges of the display window Both dimensions are scaled by the same amount so there is no aspect distortion of the vector field Small red arrows on the sides of the red rectangle indicate which dimension will expand to meet the display window boundaries upon release of the left mouse button After the rescaling the red rectangle remains in the display window briefly surrounding the same region of the vector field but at the new scale A click and drag with the right mouse button displays a blue rectangle that changes size as the mouse is dragged When the right mouse button is released the vector field is rescaled so that all of the vector field currently visible in the display window fits the size of the blue rectangle Both dimensions are scaled by the same amount so there is no aspect distortion of the vector field Small blue arrows on the sides of the blue rectangle indicate the dimension in which the vector field will shrink to exactly transform the display window size to the blue rectangle size After the rescaling the blue rectangle remains in the display window briefly surrounding the same region of the vector field now centered in the display window and at the new scale When the zoom value
62. loads and runs from the beginning If set to 1 then when loading the problem a check is made for a pre existing restart checkpoint file If one is found then the problem resumes from the state saved in that file If no checkpoint file is found then an error is raised If the restart option is set to 2 then a checkpoint file is used if one can be found but if not then the problem loads and runs from the beginning without raising an error See the Oxs_Driver documentation Sec 7 3 5 page 77 for information on checkpoint files threads lt count gt The option is available on threaded Sec 2 3 4 builds of Oxs The count parameter is the number of threads to run The default count value is set by the oommf_thread_count value in the config platforms file for your platform but may be overridden by the OOMMF_THREADS environment variable or this command line option In most cases the default count value will equal the number of processing cores on the system this can be checked via the command tclsh oommf tcl platform numanodes lt nodes gt This option is available on NUMA aware Sec 2 3 4 builds of Oxs The nodes parameter must be either a comma separated list of 0 based node numbers the keyword auto or the keyword none In the first case the num bers refer to memory nodes These must be passed on the command line as a single parameter so either insure there are no spaces in the list or else protect the spaces with outly
63. may seem a bit complicated but the examples in the next section should make things clearer 10 2 2 4 Sample task scripts The first sample task script Fig 1 is a simple exam ple that runs the 3 micromagnetic simulations described by the MIF 1 x files taskA mif taskB mif and taskC mif It is launched with the command tclsh oommf tcl batchmaster simpletask tcl This example uses the default slave launch script so a single slave is launched on the current machine and the 3 simulations will be run sequentially Also no slave initialization script is given so the default procs in batchsolve tcl are used Output will be magnetization states and tabular data at each control point stored in files on the local machine with base names as specified in the MIF files The second sample task script Fig 2 builds on the previous example by defining BatchTaskIterationCallback and BatchTaskRelaxCallback procedures in the slave init 121 script The first set up to write tabular data every 10 iterations while the second writes tabular data on each control point event The data is written to the output file specified by the Base Output Filename entry in the input MIF files Note that there is no magnetiza tion vector field output in this example This task script is launched the same way as the previous example tclsh oommf tcl batchmaster octrltask tcl The third task script Fig 3 isa more complicated example running concurrent processes on tw
64. multiple copies of Boxsi simultaneously or run Boxsi in parallel with some other application s then set the thread count to a number smaller than the number of processing cores and restrict Boxsi to some subset of the memory nodes with the numanodes option and an explicit nodes list The environment variable OOMMF_NUMANODES may be used to override the default none setting but is subordinate to the command line setting if any miffile Load and solve the problem found in miffile which must be either in the MIF 2 format or convertible to that format by mifconvert Required Although Boxsi cannot be launched by mmLaunch nonetheless a limited graphical interactive interface for Boxsi is provided through mmLaunch in the same manner as is done for Oxsii Each running instance of Boxsi is included in the Threads list of mm Launch along with a checkbutton This button toggles the presence of a user interface window Inputs Boxsi loads problem specifications directly from disk as requested on the command line The format for these files is the MIF 2 Sec 17 1 format the same as used by the Oxsii interactive interface The MIF 1 1 and MIF 1 2 formats used by the 2D solver mmSolve2D can also be input to Boxsi which will automatically call the command line tool mifconvert Sec 16 11 to convert from the MIF 1 x format to the MIF 2 format on the fly Sample MIF 2 files can be found in the directory oommf app oxs examples Output
65. nanosecond m is the unit magnetization direction e Total energy in joules e Delta E change in energy between last step and current step in joules e dE dt derivative of energy with respect to time in joules per second e Energy calc count number of times total energy has been calculated The vector field outputs are e Total field total effective field H in A m e mxH torque in A m m is the unit magnetization direction H is the total effective field e dm dt derivative of spin m with respect to time in radians per second Example octant mif Oxs_RungeKuttaEvolve Time evolver implementing several Runge Kutta methods for integrating the Landau Lifshitz Gilbert ODE 2 3 with step size control In most cases it will greatly outperform the Oxs_EulerEvolve class The Specify block has the form Specify Oxs_RungeKuttaEvolve name alpha a gamma_LL 7 gamma_G y do_precess precess allow_signed_gamma signed gamma min_timestep minimum_stepsize max_timestep maximum_stepsize fixed_spins atlas_spec region region2 start dm Am start_dt start_timestep 69 stage_start scontinuity error_rate rate absolute _step_error abs_error relative_step_error rel_error energy_precision eprecision min_step_headroom min_headroom max_step_headroom maz_headroom reject_goal reject_proportion method subtype Most of these options appear also in the Oxs_EulerEvolve class The repeats have the same meaning as in that cl
66. necessary Here routinecount is the number of routines and paramlcount is the number parameters including name1 needed by the first routine etc Note that all lengths are in meters The coordinates in the simulation lie in the first octant running from 0 0 0 to Part Width Part Height Part Thickness 17 3 6 Output specification e Base Output Filename Default base name used to construct output filenames 215 Magnetization Output Format Format to use in the OVF Sec 19 1 data block for exported magnetization files Should be one of binary 4 default binary 8 or text format spec where format spec is a C printf style format code such as h 17g Optional Total Field Output Format Analogous to the Magnetization Output Format but for total field output files Optional with default binary 4 Data Table Output Format Format to use when producing data table style scalar output such as that sent to mmDataTable Sec 11 mmGraph Sec 12 and mmArchive Sec 14 Should specify a C printf style format code such as the default 16g Optional 17 3 7 Miscellaneous Converge mxh Value Nominal value to use as a stopping criterion When m x h i e Mx H 2 at all spins in the simulation is smaller than this value it is assumed that a relaxed equilibrium state has been reached for the current applied field This is a dimensionless value NOTE This Record Identifier is d
67. option may be useful if mmGraph is being fed data from multiple sources The Options Key selection toggles the key legend display on and off The key may also be repositioned by dragging with the left mouse button If curves are selected off both the yl and y2 menus then a horizontal line in the key separates the two sets of curves with the labels for the yl curves on top If the Options Auto Reset selection is enabled then when a new table is detected all previously existing axis menu labels that are not present in the column list of the new data set are deleted along with their associated data mmGraph will detect a new table when results from a new problem are received or when data is input from a file If Options Auto Reset is not selected then no data or axis menu labels are deleted and the axes menus will show the union of the old column label list and the new column label list If the axes menus grow too long the user may manually apply the File Reset command to clear them The last command on the options menu is Options Smooth If smoothing is disabled then the data points are connected by straight line segments If enabled then each curve is rendered as a set of parabolic splines which do not in general pass through the data points This is implemented using the smooth 1 option to the Tcl canvas create line command see that documentation for details A few controls are available only using the mouse If the mouse pointer is p
68. pairwise specification model used by Oxs Exchange6Ngbr The exchange energy at a cell is computed across its nearest 6 neighbors N using the formula Ei 5 Aij ef aD 2 where A is the discretization step size from cell to cell j in meters and JAA Ajet Cet Asay with Aij eff Q if A and Aj are 0 Note that Aij eg satisfies the following properties Ales cit A jiff Ana A if A4 A Ta Age 0 Additionally if A and A are non negative min A A lt Agee lt max Aj A Evaluating the exchange energy with this formulation of Ajj is equivalent to finding the minimum possible exchange energy between cells and 7 under the assumption that A and A are constant in each of the two cells Similar consid erations are made in computing the exchange energy for a 2D variable thickness model 16 The Specify block for Oxs_ExchangePtwise has the form Specify Oxs ExchangePtwise name A scalarfield_spec where scalarfield_spec is an arbitrary scalar field object Sec 7 3 6 returning the desired exchange coefficient in J m Example antidots filled mif 55 Oxs_TwoSurfaceExchange Provides long range bilinear and biquadratic exchange Typically used to simulate RKKY style coupling across non magnetic spacers in spinvalves The specify block has the form Specify Oxs TwoSurfaceExchange name sigma value sigma2 value surfacel atlas atlas_spec region region_label scalarfield scalarfi
69. rxmax rymax rzmax truncate lt 0 1 gt v level valfunc label units fcnexpr infile where average lt space plane line point ball gt Specify type of averaging Selection of Space averaging results in the output of one data line per input file consisting of the average Uz Uy and v field values in the selected region see region option below For example in magnetization files vs vy and v correspond to M My and M If plane http www itworld com AppDev 1461 UIR000330xvfb 154 or line is selected then the output data table consists of multiple lines with 4 or 5 columns per line respectively The last 3 columns in both cases are the vz vy and v averaged over the specified axes parallel affine subspace i e plane or line In the plane case the first column specifies the averaging plane offset along the coordinate axis normal to the plane see axis option below In the line case the first 2 columns specify the offset of the averaging line in the coordinate plane perpendicular to the line If the averaging type is point then no averaging is done and the output consists of lines of 6 column data one line for each point in the selected region where the first 3 columns are the point coordinates and the last 3 are the vz vy and v values at the point If the type is ball then one line is output for each sample point for which a ball of radius brad see ball_radius option centered about that point lie
70. script in Sec 10 2 2 4 For commands accepted by mif objects see the file mmsinit cc Another object than can be gainfully manipulated is solver which is defined in solver tcl If you want to run more than one task at a time then the TaskInfo method AppendSlave will have to be invoked This takes the form TaskInfo AppendSlave lt spawn count gt lt spawn command gt where lt spawn command gt is the command to launch the slave process and lt spawn count gt is the number of slaves to launch with this command Typically lt spawn count gt should not be larger than the number of processors on the target system The default value for this item which gets overwritten with the first call to TaskInfo AppendSlave is 1 Oc_Application Exec batchslave tk 0 connect_info batchsolve tcl The Tcl command Oc_Application Exec is supplied by OOMMEF and provides access to the same application launching capability that is used by the OOMMF bootstrap applica tion Sec 5 Using a lt spawn command gt of Oc_Application Exec instead of exec tclsh Zoommf saves the spawning of an additional process The default lt spawn command gt launches the batchslave application with connection information provided by batchmaster and using the auxscript batchsolve tcl Before evaluating the lt spawn command gt batchmaster applies several percent style sub stitutions useful in slave launch scripts tclsh Yoommf connect_info Yoommf_root and T
71. set pi expr 4 atan 1 0 set mu0 expr 4 pix1e 7 Specify Oxs_UZeeman subst 197 comment Set units to mT Hscale expr 0 001 mu0 Hrange 0 0 10 0 O 2 10 0O 0O 10 O0 0 2 Note that the subst command is evaluated at global scope so that the global variable muO is directly accessible 17 1 5 Sample MIF 2 1 File MIF 2 1 All units are SI This file must be a valid Tcl script Initialize random number generators with seed 1 RandomSeed 1 HH HH HOH H HH FH OH OF OF Individual Oxs_Ext objects are loaded and initialized via Specify command blocks The following block defines the extents in meters of the volume to be modeled The prefix Oxs_BoxAtlas specifies the type of Oxs_Ext object to create and the suffix WorldAtlas is the name assigned to this particular instance Each object created by a Specify command must have a unique full name here Oxs_BoxAtlas WorldAtlas If the suffix is not explicitly given then the default is automatically assigned References may be made to either the full name or the shorter suffix instance name here WorldAtlas if the latter is unique See the Oxs_TimeDriver block for some reference examples Specify Oxs_BoxAtlas WorldAtlas xrange 0 500e 9 yrange 0 250e 9 zrange 0 10e 9 The Oxs_RectangularMesh object is initialized with the 198 discretization cell size in meters Specify Oxs_Rectangu
72. simple operation of reading in a MIF file and then writing it back out may alter the file Each instance of mmProbEd contains exactly one problem description at a time When the option net 1 is active the default each also services requests from client applications typically solvers for the problem description it contains Controls The Options menu allows selection of MIF output format either MIF 1 1 or MIF 1 2 may be selected This affects both File Save as file and mmSolve2D server output See the MIF 1 2 Sec 17 4 page 218 format documentation for details on the differences between these formats The main panel in the mmProbEd window contains buttons corresponding to the sec tions in a MIF 1 x problem description Selecting a button brings up another window through which the contents of that section may be edited The MIF sections and the elements they contain are described in detail in the MIF 1 1 and MIF 1 2 documentation Only one editing window is displayed at a time The windows may be navigated in order using their Next or Previous buttons The Material Parameters edit window includes a pull down list of pre configured ma terial settings NOTE These values should not be taken as standard reference values for these materials The values are only approximate and are included for convenience and as examples for users who wish to supply their own material types with symbolic names To in troduce additional material types ed
73. stopping time value specifies the maximum Simulation time i e the Landau Lifshitz Gilbert ODE 2 3 time allowed per stage For example if time_criteria is 107 then no stage will evolve for more than 1 ns If there were a total of 5 stages in the simulation then the total simulation time would be not more than 5 ns The third way to terminate a stage is with a stage_iteration_limit This is a limit on the number of successful evolver steps allowed per stage A stage is considered complete when any one of these three criteria are met Each of the criteria may be either a single value which is applied to every stage or else a grouped list Sec 17 1 3 3 of values If the simulation has more stages than a criteria list has entries then the last criteria value is applied to all additional stages These stopping criteria all provide a default value of 0 meaning no constraint but usually at least one is specified since otherwise there is no automatic stage termination control For quasi static simulations a stopping dm dt value in the range of 1 0 to 0 01 is reasonable the numerical precision of the energy calculations usually makes in not possible to obtain dm dt much below 0 001 degree per nanosecond The total_iteration_limit stage_count and stage_count_check parameters involve simulation run completion conditions The default value for the first is 0 interpreted as no limit but one may limit the total number of steps performed
74. tclsh oommf tcl launchhost 0 export OOMMF_HOSTPORT tclsh oommf tcl mmArchive tclsh oommf tcl boxsi sample mif tclsh oommf tcl killoommf all The second line OOMMF_HOSTPORT launches the host server on a random port the port selected is printed to stdout by launchhost and sets the environment variable OOMMF_HOSTPORT Note in particular the backticks around the launchhost command which invoke command execution The subsequent commands launch an instance of mmArchive in the back ground and run boxsi on the problem described by sample mif By default boxsi runs in the foreground When boxsi returns the killoommf command is used to terminate all OOMMF processes in this session Alternatively the boxsi command option kill may be used to the same effect as killoommf For csh and derivatives use setenv OOMMF_HOSTPORT tclsh oommf tcl launchhost 0 in place of the two OOMMF_HOSTPORT commands in the above example 16 10 Calculating H Fields from Magnetization mag2hfield The mag2hfield utility takes a MIF 1 1 micromagnetic problem specification file mif see Sec 17 3 and a magnetization file omf see Sec 19 and uses the mmSolve2D Sec 10 1 computation engine to calculate the resulting component self magnetostatic exchange crys talline anisotropy Zeeman and total energy and or H fields The main use of this utility to study the fields in a simulation using magnetization files generated by an earlier mm Solve2D r
75. the NUMA aware code you must specify the numanodes option on the oxsii boxsi command line or set the the environment variable OOMMF_NUMANODES Check the Oxs documentation Sec 7 for details 2 3 5 Managing OOMMEF Platform Names OOMMEF software classifies computing platforms into different types using the scripts in the directory config names relative to the root directory of the OOMMF distribution Each type of computing platform is assigned a unique name These names are used as directory names and in index and configuration files so that a single OOMMF installation may contain platform dependent sections for many different types of computing platforms To learn what name OOMMF software uses to refer to your computing platform run tclsh oommf tcl platform in the OOMMF root directory Changing the name OOMMEF assigns to your platform First use pimake Sec 16 15 to build the target distclean to clear away any compiled executables built using the old platform name tclsh oommf tcl pimake distclean Then to change the name OOMMEF software uses to describe your platform from foo to bar simply rename the file config names foo tcl to config names bar tcl and config platforms foo tcl to config platforms bar tcl After renaming your platform type you should recompile your executables using the new platform name 13 Adding a new platform type If oommf tcl platform reports the platform name unknown then none of the scripts
76. the OVF 2 0 format supports the same types of data as the OVF 1 0 format but another common case is N 1 which represents scalar fields such as energy density in say J m The recommended file extensions for OVF files are omf for magnetization files ohf for magnetic field H files obf for magnetic flux density B files oef for energy density files or ovf for generic files 19 1 The OVF 1 0 format A commented sample OVF 1 0 file is provided in Fig 11 An OVF file has an ASCII header and trailer and a data block that may be either ASCII or binary All non data lines begin with a character double mark the start of a comment which continues until the end 220 of the line There is no line continuation character Lines starting with a but containing only whitespace characters are ignored All non empty non comment lines in the file header are structured as label value pairs The label tag consists of all characters after the initial up to the first colon character Case is ignored and all space and tab characters are eliminated The value consists of all characters after the first colon continuing up to a comment designator or the end of the line The first line of an OVF file should be a file type identification line having the form OOMMF rectangular mesh v1 0 or OOMMF irregular mesh v1 0 where the value rectangular mesh v1 0 or irregular mesh v1 0 i
77. the base problem mesh Examples randomshape mif stdprob1 mif 84 Oxs_ScriptScalarField Analogous to the parallel Oxs_ScriptVectorField class this class produces a scalar field dependent on a Tcl script and optionally other scalar and vector fields The Specify block has the form Specify Oxs_ScriptScalarField name script Tcl_script script_args args_request scalar_fields scalar_field_spec vector_fields vector_field_spec atlas atlas_spec xrange rmin zmar yrange ymin ymaz zrange zmin zmar For each point of interest the specified script is called with the arguments requested by script_args appended to the command as explained in the User Defined Support Procedures section Sec 17 1 3 6 of the MIF 2 file format documentation The value for script_args should be a subset of rawpt relpt minpt maxpt span scalars vectors If rawpt is requested then when the Tcl proc is called at the corresponding spot in the argument list the x y z values of point will be placed in problem coordinates in meters The points so passed will usually be node points in the simulation dis cretization the mesh but this does not have to be the case in general The relpt minpt maxpt and span rely on a definition of a bounding box which is an axes parallel parallelepiped The bounding box must be specified by either referencing an atlas or by explicitly stating the range via the three entries xrange yrange zra
78. the current applied field The control point specs are specified as type value pairs There are 3 recognized control point types torque time and iteration If a torque pair is given then the simulation at the current applied field is ended when m x hl i e M x H M at all spins in the simulation is smaller than the specified torque value dimensionless If a time pair is given then the simulation at the current field is ended when the elapsed simulation time for the current field step reaches the specified time value in seconds Similarly an iteration pair steps the applied field when the iteration count for the current field step reaches the iteration value If multiple control point specs are given then the applied field is advanced when any one of the specs is met If no control point specs are given on a range line then the Default Control Point Spec is used For example consider the following Field Range line Field Range 000 0500 5 torque 1e 5 time 1e 9 This specifies 6 applied field values 0 0 0 0 01 0 0 0 02 0 0 0 05 0 0 in Tesla with the advancement from one to the next occurring whenever m x hl is smaller than le 5 for all spins or when 1 nanosecond simulation time has elapsed at the current field If torque was not specified then the applied field would be stepped at 1 2 3 4 and 5 ns in simulation time The Field Range record is optional with a default value of 0000
79. the output bitmap may increase dramatically 162 misc boundarypos Placement of the bounding polygon either back or front i e either behind or in front of the rendered arrows and pixel elements misc matwidth Specifies the width in pixels of a mat frame around the outer edge of the image The mat is drawn in front of all other objects To disable set matwidth to 0 misc matcolor Color of the mat misc width misc height Maximum width and height of the output bitmap in pixels If misc crop is enabled then one or both of these dimensions may be shortened misc crop If disabled 0 then any leftover space in the bitmap of dimensions misc width by misc height after packing the image are filled with the background color If en abled 1 then the bitmap is cropped to just include the image with the margin specified by misc margin NOTE Some movie formats require that bitmap dimen sions be multiples of 8 or 16 For such purposes you should disable misc crop and specify appropriate dimensions directly with misc width and misc height The default configuration file shown in Fig 5 page 164 can be used as a starting point for user configuration files You may also use configuration files produced by the File Write config command in mmDisp although any of the above avf2ppm specific parameters that you wish to use will have to be added manually using a plain text editor You may omit any entries that you do not want to chan
80. this particular example K1 is desired uniform homogeneous throughout the simulation region so the trivial Oxs_UniformScalarField class is used for initialization to the value 530 x 10 J m In the case of uniform fields scalar or vector a shorthand notation is available that implicitly supplies a uniform Oxs_Ext field class Specify Oxs_UniaxialAnisotropy axis 100 K1 530e3 which is equivalent to 189 Specify Oxs_UniaxialAnisotropy axis Oxs_UniformVectorField vector 100 F K1 Oxs_UniformScalarField value 530e3 While embedding 0xs_Ext objects inside Specify blocks can be convenient it is important to remember that such objects are not available to any other Oxs_Ext object only objects declared via top level Specify blocks may be referenced from inside other Specify blocks Also embedded Oxs_Ext objects cannot directly provide user output Furthermore the only Oxs_Energy energy objects included in energy and field calculations are those declared via top level Specify blocks For this reason Oxs_Energy terms are invariably created via top level Specify blocks and not as embedded objects 17 1 3 3 Grouped lists As noted earlier sometimes the value portion of a label value pair will be a list Some Oxs objects support grouped lists which provide a type of run length encoding for lists Consider the sample list asi 12 Oe a Ot 0 ee gt eral In a grouped list the middle run of 1 2 s may be r
81. toggles the presence of a user interface window through which the user may control that instance of mmArchive Inputs mm Archive accepts vector field and data table style input from client applications typically running solvers on its network socket interface Outputs The client applications that send data to mmArchive control the flow of data mmArchive copies the data it receives into files specified by the client There is no interactive control to 149 select the names of these output files A simple status line shows the most recent vector file save or data table file open close event For data table output if the output file already exists then the new data is appended to the end of the file The data records for each session are sandwiched between Table Start and Table End records See the ODT format documentation Sec 18 for explanation of the data table file structure It is the responsibility of the user to insure that multiple data streams are not directed to the same data table file at the same time For vector field output if the output file already exists then the old data is deleted and replaced with the current data See the OVF documentation Sec 19 for information about the vector field output format Controls The Exit in the mmLaunch supplied user interface terminates mmArchive Simply clos ing the user interface window does not terminate mmArchive but only hides the control window To kill mm
82. types If oommf tcl platform reports the platform name to be unknown then you will need to add some configuration files to help OOMMF assign a name to your platform type and associate with that name some of the key features of your computer See the section on Managing OOMMF platform names Sec 2 3 5 for further instructions The second line reports the operating system version which is mainly useful to OOMMF developers when fielding bug reports The third line reports what C compiler will be used to build OOMMF from its C source code If you downloaded an OOMMF release with pre compiled binaries for your platform you may ignore this line Otherwise if this line reports none selected or if it reports a compiler other than the one you wish to use then you will need to tell OOMMF what compiler to use To do that you must edit the appropri ate configuration file for your platform Continuing the example above one would edit the file config platforms linux x86_64 tcl Editing instructions are contained within the file On other platforms the name linux x86_64 in config platforms linux x86_64 tcl should be replaced with the platform name OOMMF reports for your platform For example on a 32 bit Windows machine using an x86 processor the corresponding configuration file is config platforms wintel tcl The next group of lines describe the Tcl configuration OOMMF finds on your platform The first couple of lines tclsh runn
83. user may save and display intermediate results either interactively or via scheduling based on iteration and stage counts Problem descriptions in the MIF 1 1 and MIF 1 2 formats can also be input They are automatically passed to mifconvert Sec 16 11 for implicit conversion to MIF 2 format Launching Oxsii may be started either by selecting the Oxsii button on mmLaunch or from the com mand line via tclsh oommf tcl oxsii standard options exitondone lt 0 1 gt nice lt 0 1 gt parameters params pause lt 0 1 gt restart lt 0 1 gt threads lt count gt numanodes lt nodes gt miffile where exitondone lt 0 1 gt Whether to exit after solution of the problem is complete Default is to simply await the interactive selection of another problem to be solved nice lt 0 1 gt If enabled i e 1 then the program will drop its scheduling priority after startup The default is 1 i e to yield scheduling priority to other applications parameters params Sets MIF 2 Sec 17 1 file parameters The params argument should be a list with an even number of arguments corresponding to name value pairs Each name must appear in a Parameter statement Sec 17 1 2 in the input MIF file The entire name value list must be quoted so it is presented to Oxsii as a single item on the command line For example if A and Ms appeared in Parameter statements in the MIF file then an option like parameters A
84. 00 0 Default Control Point Spec List of control point type value pairs to use as step ping criteria for any field range with no control point specs This is a generaliza tion of and replacement for the Converge mzh Value record Optional with default storque 16 5 Field Type Applied external field routine and parameters if any This is optional with default Uniform At most one record of this type is allowed but the Multi type may be used to apply a collection of fields The nominal applied field NAF is stepped through the Field Ranges described above and is made available to the applied field routines which use or ignore it as appropriate The following Field Type routines are available Uniform Applied field is uniform with value specified by the NAF 214 Ribbon relcharge x0 yO x1 y1 height Charge Ribbon lying perpendicular to the xy plane Here relcharge is the charge strength relative to Ms and x0 y0 xl yl are the endpoints of the ribbon in meters The ribbon extends height 2 above and below the calculation plane This routine ignores the NAF Tie rfx rfy rfz x0 yO x1 yl ribwidth The points x0 y0 and x1 y1 define in meters the endpoints of the center spine of a rectangular ribbon of width ribwidth lying in the xy plane The cells with sample point inside this rectangle see an applied field of rfx rfy rfz in units relative to Ms If the field is large then the magnetizations
85. 114 115 expires 28 launching of 28 animations 160 announcements 2 antialias 162 application any2ppm 34 107 115 153 212 avf2odt 154 avf2ovf 95 158 avf2ppm 136 143 160 163 avf2ps 136 163 avfdiff 167 batchmaster 117 batchslave 115 batchsolve 114 116 179 bootstrap 29 31 Boxsi 179 boxsi 39 crc32 167 FileSource 105 209 ghostscript 165 gzip 135 Internet Explorer 11 147 killoommf 169 launchhost 170 mag2hfield 171 make 176 mifconvert 24 172 179 mmArchive 21 23 25 37 79 127 149 202 mmDataTable 21 22 24 37 79 126 129 130 mmDisp 1 21 23 25 37 109 116 133 134 149 160 163 202 mmGraph 21 25 37 79 113 127 129 149 233 mmHelp 151 mmLaunch 21 32 34 37 40 42 108 113 114 mmProbEd 21 102 105 115 179 236 mmsSolve 211 mmSolve2D 21 22 107 114 115 179 209 Netscape 11 145 odtcols 173 OOMMF Batch System 114 Oxs 149 Oxsii 21 23 34 179 pidinfo 174 175 pimake 9 176 ppmquant 162 ppmtogif 162 rsh 117 120 122 telsh 3 web browser 145 151 Windows Explorer 19 31 wish 3 Xvfb 3 30 154 architecture 27 batch processing see application OOMMF Batch Sys tem bitmap files see file bitmap Borland C see platform Windows Borland C boundary 1 139 143 bug reports see reporting bugs cell size 212 citation information 236 client 27 client server architecture 27 color discretization 142 map 137
86. 115 initial 1 magnetization initial 213 margin 143 mask file see file mask materials 209 max angle 110 memory use 131 mesh see grid MIF see file mif MIF 2 1 Commands 181 MIF 2 1 Overview 179 MIF 2 2 Commands 202 mmLaunch user interface 32 33 37 42 108 113 149 movies see animations mxh see simulation mxh NetPBM 162 network socket 1 39 113 119 bug see platform Windows network socket bug nicknames 30 175 182 NUMA 7 12 13 36 41 44 see also paral lelization OBS see application OOMMF Batch System ODE Landau Lifshitz 1 66 69 71 111 112 210 211 predictor corrector 112 Runge Kutta 113 step size 216 OID s 174 175 optimization 11 options tcl 10 output schedule 22 23 25 109 Oxs_Ext child classes 45 Oxs_AffineOrientScalarField 89 Oxs_AffineOrient VectorField 97 Oxs_AffineTransformScalarField 90 Oxs_AffineTransformVectorField 97 Oxs_AtlasScalarField 83 Oxs_AtlasVectorField 93 239 Oxs_BoxAtlas 46 Oxs_CGEvolve 73 Oxs_CubicAnisotropy 53 Oxs_Demag 59 Oxs_EllipsoidAtlas 51 Oxs_EulerEvolve 66 Oxs_Exchange6Nebr 53 Oxs_ExchangePtwise 55 Oxs_FileVectorField 94 Oxs_FixedZeeman 60 Oxs_ImageAtlas 46 Oxs_ImageScalarField 91 Oxs_ImageVectorField 100 Oxs_LabelValue 101 Oxs_LinearScalarField 84 Oxs_MaskVectorField 99 Oxs_MinDriver 80 Oxs_MultiAtlas 49 Oxs_PlaneRandomVectorField 96 Oxs_RandomScalarField 84 Oxs_RandomSiteExchange 58
87. 13e 12 Ms 800e3 could be used to set A to 13e 12 and Ms to 800e3 The quoting mechanism is shell operating system specific refer to your system documentation for details pause lt 0 1 gt If disabled i e 0 then the program automatically shifts into Run mode after loading the specified miffile The default is 1 i e to Pause once the problem is loaded This switch has no effect if miffile is not specified 35 restart lt 0 1 gt Controls the initial setting of the restart flag and thereby the load restart behavior of any miffile specified on the command line The restart flag is described in the Controls section below The default value is 0 i e no restart threads lt count gt The option is available on threaded Sec 2 3 4 builds of Oxs The count parameter is the number of threads to run The default count value is set by the oommf_thread_count value in the config platforms file for your platform but may be overridden by the OOMMF_THREADS environment variable or this command line option In most cases the default count value will equal the number of processing cores on the system this can be checked via the command tclsh oommf tcl platform numanodes lt nodes gt This option is available on NUMA aware Sec 2 3 4 builds of Oxs The nodes parameter must be either a comma separated list of 0 based node numbers the keyword auto or the keyword none In the first case the num bers refer to memor
88. 26 129 134 149 17 14 Variable Substitution cos sea bee 3 bee ewe Ree RH d 197 17 15 Sample MIP 2 1 File 2 2 baie ee ee ee ee ee 198 Be eee ee ee we Oo oe oe Ee eee ee ee ee ee es 201 17 2 1 Differences between MIF 2 2 and MIF 2 1 Formats 201 17 2 2 MIF 2 2 New Extension Commands 000 202 17 2 3 Sample MIF 2 2 File gt aes sceso Hee Dee ee ee eM 204 Te E ae O Sw E He es SO SG eS 209 IT 3 1 Material parameters sp soes sear Y Ow SK eR ew 209 17 32 Demag specification s e e o ei ace hee ee aia Goa E o OS 211 Iroso OP POEs eo aa Ew ee a Sree Be ee ee ee n 211 Lio Imitial magnetization e e e sioe Sea ee a ee eR OE e e F 213 17 39 90 Experiment p ramet rsS 2 2 rtas e isso ie np Ee Ree ES 213 17 36 Outp tspecd cation lt a co sse braa a ee a e e a a 215 T3 Miscelaneois co sa ra saoe DR naie AREA RE hw 4 216 ITA MIP I2 ioie E oni aoan e Soe aA Bd a Se SB eS Be S 218 18 Data Table File Format ODT 219 19 Vector Field File Format OVF 219 19 1 The OVF LO PO s s roi aat Ea a BOS e a a eia k BE eia a oa 220 19 1 1 Segment Header block naaa a 221 Pe Data Dod eas ra prat RA Bree we Gee we ee a pu a a 222 193 The OVF 20 lommal sc ba te AAS RE Yew ee eS ees 225 199 The OVF O00 format sw e sice sa da no GA ow SAB ES r AB ce rd 227 20 Troubleshooting 230 21 References 234 22 Credits 236 iii Disclaimer This software was developed at the National Institute of Standards and Tec
89. 2g scalar_field_output_format text 4g scalar_field_output_meshtype irregular vector_field_output_format binary 4 HHHHHHHHHHHHHHH Rogue grain If RoguePt is an empty string then no rogue grain is selected OTOH If RoguePt is set to a three item list consisting of x y and z coords in the problem coordinate system i e in meters then the grain containing that point is individually set as specified below Parameter RoguePt 263 5e 9 174 5e 9 3e 9 HHHHHHHHHHHHHEH Support procs proc Ellipse Ms x y z set x expr 2 x 1 set y expr 2 y 1 if x x y y lt 1 0 return Ms return 0 0 HHHHHHHHHHHHHHH Material constants set Ms 1 40e6 set Ku 530e3 set A 8 1e 12 HHHHHHHHHHHHHHH Atlas and mesh set xsize 400e 9 set ysize 400e 9 set xycellsize 1 0e 9 set zcellsize 3 0e 9 205 set grain_count 260 set grain_map polycrystal map mif ppm set colormap for set i 0 i lt grain_count incr i lappend colormap format 06x i lappend colormap i Specify Oxs_ImageAtlas world subst xrange 0 xsize yrange 0 ysize zrange 0 thickness viewplane xy image grain_map colormap colormap matcherror 0 0 Specify Oxs_RectangularMesh mesh subst cellsize xycellsize xycellsize zcellsize atlas world TERE TETETETETETE AE HEHEHE BE PETE PEE HEH HEHE EE Uniaxial Anisotropy Generate TEXTURED random unit vector set phirange ex
90. 53 160 184 185 212 bmp 153 161 212 configuration 130 131 135 136 162 166 conversion 153 154 158 160 163 171 172 data table 23 25 109 115 120 121 130 150 154 173 216 219 difference 167 gif 153 162 212 hosts see platform Windows hosts file HTML 151 log 110 114 116 magnetization 114 121 171 216 mask 34 46 49 107 115 194 212 MIF 172 179 MIF 1 1 102 MIF 1 2 102 MIF 1 x 105 111 115 116 119 122 238 obf see file vector field odt see file data table ohf see file vector field omf see filesmagnetization options tcl 10 ovf see file vector field pdf 165 PostScript 163 ppm 153 161 162 212 svf 220 223 227 VecFil 220 vector field 23 25 109 116 135 136 138 147 150 154 158 160 163 167 171 213 216 219 227 vio 154 158 167 213 220 GetMifFilename command MIF 202 GetMifParameters command MIF 202 grid 1 112 145 159 222 grouped lists MIF 190 gyromagnetic ratio 210 host service directory 27 32 expires 28 launching of 28 installation 3 Tcl Tk 6 8 instance name MIF 2 181 Internet see TCP IP iteration 109 115 Landau Lifshitz see ODE Landau Lifshitz launch by account service directory 27 28 command line arguments 29 31 foreground 29 from command line 29 standard options 30 31 version requirement 29 with bootstrap application 29 with mmLaunch 33 license iv magnetization 110
91. 7 DE 40 for 8 byte mode The data immediately follow the check value The structure of the data depends on whether the meshtype declared in the header is irregular or rectangular For irregular meshes each data element is a 6 tuple consisting of the x y and z components of the node position followed by the x y and z components of the field at that position Ordering among the nodes is not relevant The number of nodes is specified in the pointcount line in the segment header For rectangular meshes data input is field values only in x y z component triples These are ordered with the x index incremented first then the y index and the z index last This is nominally Fortran order and is adopted here because commonly x will be the longest dimension and z the shortest so this order is more memory access efficient than the normal C array indexing of z y x The size of each dimension is specified in the xnodes ynodes znodes lines in the segment header In any case the first character after the last data item should be a newline followed by End data lt representation gt where lt representation gt must match the value in the Begin data line This is followed by a End segment line that ends the segment and hence the file Note An OVF 1 0 file with ASCII data and irregular meshtype is also a valid OVF 0 0 SVF file although as a OVF 0 0 file the value scaling as specified by va
92. 9 Overview The application Boxsi provides a batch mode interface to the Oxs micromagnetic compu tation engine A restricted graphical interface is provided but Boxsi is primarily intended to be controlled by command line arguments and launched by the user either directly from the shell prompt or from inside a batch file Within the OOMMF architecture see Sec 4 Boxsi is both a server and a client appli cation It is a client of data table display and storage applications and vector field display and storage applications Boxsi is the server of a solver control service for which the only client is mmLaunch Sec 6 It is through this service that mmLaunch provides a user interface window shown above on behalf of Boxsi A micromagnetic problem is communicated to Boxsi through a MIF 2 file specified on the command line and loaded from disk The MIF 1 x formats are also accepted they are converted to the MIF 2 format by an automatic call to mifconvert Sec 16 11 Launching Boxsi must be started from the command line The syntax is tclsh oommf tcl boxsi standard options exitondone lt 0 1 gt kill tags nice lt 0 1 gt parameters params pause lt 011 gt restart lt 0 1 2 gt threads lt count gt numanodes lt nodes gt miffile where exitondone lt 0 1 gt Whether to exit after solution of the problem is complete or to await the interactive selection of the File Exit command The default is 1 i
93. Archive the Exit button must be pressed Known Bugs mmArchive appends data table output to the file specified by the source client application e g a running solver If at the same time more than one source specifies the same file or if the the same source sends data table output to more than one instance of mmArchive then concurrent writes to the same file may corrupt the data in that file It is the responsibility of the user to ensure this does not happen there is at present no file locking mechanism in OOMMF to protect against this situation 150 15 Documentation Viewer mmHelp File Navigate Options Home Back Forward Refresh Link http math nist gov oommf Gre Next Un Previous Contents Next COMMEF Architecture Overview Up OOMMF Documentation Previous Advanced Installation Options Quick Start Example OOMMF Session STEP 1 Start up the mmLaunch window 4 Sa ns gt V Overview The application mmHelp manages the display and navigation of hypertext HTML help files It presents an interface similar to that of World Wide Web browsers Although mmHelp is patterned after World Wide Web browsers it does not have all of their capabilities mmHelp displays only a simplified form of hypertext required to display the OOMMF help pages It is not able to display many of the advanced hypertext features provided by modern World Wide Web browsers In the current release mmHelp is not able to follow http URLs I
94. Evolve attributes probdata The Specify block string for Oxs_LabelValue objects is an arbitrary Tcl list with an even number of elements The first element in each pair is interpreted as a label the second as the value The attribute option causes this list to be dropped verbatim into the surrounding object This technique is most useful if the label value pairs in the Oxs_LabelValue object are used in multiple Specify blocks either inside the same MIF file or across several MIF files into which the Oxs_LabelValue block is imported using the ReadFile MIF extension command Examples The MIF files sample rotate mif and sample reflect mif use the Oxs_LabelValue object stored in the sample attributes tcl file Refer to Sec 17 1 for details on the base MIF 2 format specification 101 8 Micromagnetic Problem Editor mmProbEd lt O gt mmProbEd 1x File Options Help lt O gt mmProbEd Material Parameters Material Parameters Material Types Add Simulation Details eee al ae oe TT Part Geometry Ms A m 800e3 Initial Hag A J m 13e 12 Experiment Parameters K1 J m 3 o SES Output Specifications Anisotropy Type Uniaxial v Cubic Miscellaneous Anisotropy Init Constant v Uniform XY v Uniform Next jo Overview The application mmProbEd provides a user interface for creating and editing micromag netic problem descriptions in the MIF 1 1 Sec 17 3 page 209 and MIF 1 2 Sec 17 4 form
95. MMF Platform Names aoaaa aa 13 2 4 Platform Specific Installation Issues a ae BRA wR eRe ee eS 15 ea Unir Comat e s conei SHS OAR e a d a BERS RO 15 242 Microsoft Windows Options lt se ss asc s sos iop p pedati 16 243 Mac OS X Conipguration o lt e ss ssc amast Ode ca po g eoi 20 3 Quick Start Example OOMMF Session 21 4 OOMMF Architecture Overview 27 5 Command Line Launching 29 6 OOMMF Launcher Control Interface mmLaunch 32 7 OOMMF eXtensible Solver 34 7 1 OOMMF eXtensible Solver Interactive Interface Oxsii 34 7 2 OOMMF eXtensible Solver Batch Interface boxsi 0 39 7 3 Standard Oxs Ext Child Classes o oaoa a aa a a a ee 45 Tot ATASE o wee eh ee ea e Rb we be ew bw ewe e 46 Ta Meba eeure eh ca eh eS e dew eM Oe do wee ke See ee 2 Ge 52 Taa EON oe Bee oe ee eee EP ae he RH 52 To Evolver e eo sea ae Geb eee ea Awe ee Sa ee Bae 66 Co Mei tt ere e a ee Be ate 2 ee e a 77 Tao Field Objects 24 64 se Bag ee See Ree eRe Bw as 82 7 3 7 MIF Support Classes 8 Micromagnetic Problem Editor mmProbEd 9 Micromagnetic Problem File Source FileSource 10 The 2D Micromagnetic Solver 10 1 The 2D Micromagnetic Intera ctive Solver mmSolve2D 2 10 2 OOMMF 2D Micromagnetic Solver Batch System 10 2 1 2D Micromagnetic Solver Batch Interface batchsolve 10 2 2 2D Micromagnetic Solver Batch Scheduling System 11 Data Table Display mmDataTable
96. OMMF software are guided by the application pimake Sec 16 15 Platform Independent Make which is distributed as part of the OOMMF release To begin building OOMMF software with pimake first change your working directory to the root directory of the OOMMF distribution cd path to oommf If you unpacked the new OOMMF release into a directory oommf which contained an earlier OOMMF release use pimake to build the target upgrade to clear away any source code files which were in a former distribution but are not part of the latest distribution tclsh oommf tcl pimake upgrade Next build the target distclean to clear away any old executables and object files which are left behind from the compilation of the previous distribution tclsh oommf tcl pimake distclean Next to build all the OOMMF software run pimake without specifying a target tclsh oommf tcl pimake On some platforms you cannot successfully compile OOMMF software if there are OOMMF programs running Check that all OOMMF programs have terminated including those in the background before trying to compile and link OOMMF When pimake calls on a compiler or other software development utility the command line is printed so that you may monitor the build process Assuming a proper configuration for your platform pimake should be able to compile and link all the OOMME software without error If pimake reports errors please first consult Troubleshooting Sec 20 to see if a
97. OOMMEF User s Guide September 28 2012 This manual documents release 1 2a4 WARNING In this alpha release the documentation may not be up to date Abstract This manual describes OOMMF Object Oriented Micromagnetic Framework a public domain micromagnetics program developed at the National Institute of Stan dards and Technology The program is designed to be portable flexible and extensible with a user friendly graphical interface The code is written in C and Tcl Tk Tar get systems include a wide range of Unix platforms Windows NT and Windows 9X Contents Disclaimer iv 1 Overview of OOMMF 1 2 Installation 3 DA REguUIrementSs lt s sicrha ERA See SHED E SE HERA SHEERS 3 De Base metalation ee se amp ow A eR Re ee BG ae eS eee a ee A 4 221 Download o a ded ye ook A we TG ee Bo A a aue a A 4 2 2 2 Check Your Platform Configuration 20 22 ee ebb es 5 22 3 Compiling and Linking s co c ro res es namina ee ene ee 9 Cae VN e ek ee rk CAA e k eS a ew RE Soe OS SG Ge 9 225 Using OONMMP Sanwate s e s cae Sane i See ce eh dee es 10 2 2 6 Reporting Problems 4 2 5 2224 bb ees bP ede ee eke eu 10 23 Advanced Installation 2 4 4 44h avaa whe Gu whee oe bed ee wo 10 2 3 1 Reducing Disk Space Usage 2 2 2 ee ee 10 232 Local Cust mizationS s sa ode Bs dee Oe dre ee eK Re eS 10 Ge RIO oe ea e ee Br ea Oe Oe ee ee 11 2 34 Parallelization o c sado carer opady neea ee aaa 11 2 3 5 Managing OO
98. OOMMEF selection terminates all applications in the Threads list and then exits mm Launch The menu Help provides the usual help facilities 33 7 OOMME eXtensible Solver The Oxs OOMMF eXtensible Solver is an extensible micromagnetic computation engine capable of solving problems defined on three dimensional grids of rectangular cells holding three dimensional spins There are two interfaces provided to Oxs the interactive interface Oxsii Sec 7 1 intended to be controlled primarily through a graphical user interface and the batch mode Boxsi Sec 7 2 which has extended command line controls making it suitable for use in shell scripts Problem definition for Oxs is accomplished using input files in the MIF 2 format Sec 17 1 This is an extensible format the standard OOMMF modules are documented in Sec 7 3 be low Files in the MIF 1 1 and MIF 1 2 formats are also accepted They are passed to mifconvert Sec 16 11 for conversion to MIF 2 format on the fly Note on Tk dependence Some MIF 2 problem descriptions rely on external image files examples include those using the Oxs_ImageAtlas class Sec 7 3 1 or those using the MIF 2 ReadFile command with the image translation specification Sec 17 1 2 If the image file is not in the PPM P3 text format then the any2ppm application may be launched to read and convert the file Since any2ppm requires Tk at the time the image file is read a valid display must be available See
99. Oxsii to control the 3D solver e Click on mmDisp mmGraph and or mmDataTable depending on what form of output you want Use mmArchive to save data to disk STEP 3a Run a 2D problem Load problem e On the mmLaunch window click on the mmProbEd button e On the mmProbEd window make menu selection File Open An Open File dialog window will appear On this window Double click in the Path subwindow to change directories Several sample problems can be found in the directory oommf app mmpe examples To load a problem double click on a mif file e g probl mif from the list above the Filter subwindow 21 e Modify the problem as desired by clicking on buttons from the main mmProbEd window e g Material Parameters and fill out the pop up forms A completely new problem may be defined this way e If desired the defined problem may be stored to disk via the File Save as menu selection Initialize solver e On the mmLaunch window click on the mmSolve2D button to launch an instance of the program mmSolve2D e Wait for the new solver instance to appear in the Threads column in the mm Launch window e Check the box next to the mmSolve2D entry in the Threads column A window containing an mmSolve2D interface will appear e On the mmSolve2D window Check Problem Description under Inputs Check mmProbEd under Source Threads Click LoadProblem A status line will indicate the problem is load
100. PrP Pe proc MyShape xrel yrel znotused global mask Make mask accessible inside proc set Ms 8e5 Saturation magnetization of element set xindex expr int floor xrel 16 set yindex expr 5 int floor yrel 6 set index expr yindex 16 xindex index references point in mask corresponding to xrel yrel return expr lindex mask index Ms The variable mask holds a Tcl list of 0 s and 1 s defining a part shape The mask is brought into the scope of the MyShape proc via the Tcl global command The relative x and y coordinates are converted into an index into the list and the proc return value is either 0 or 8e5 depending on whether the corresponding point in the mask is 0 or 1 This is essentially the same technique used in the ColorField proc example presented in the ReadFile MIF extension command documented above Sec 17 1 2 except that there the data structure values are built from a separate image file rather than from data embedded inside the MIF file 17 1 3 7 User defined scalar outputs OOMMEF Oxs_Ext objects support a general method to allow users to define scalar DataTable outputs derived from vector field outputs These scalar outputs are defined by user_output sub blocks inside Specify blocks The format is 194 user_output name output_name source field source select_field weighting normalize norm_request exclude_OMs novacuum user_scaling scale units units The fir
101. The names may vary somewhat between Linux distributions but the first typically includes the executable numactl1 and the second includes the header file numa h Once the numactl package is installed you can run the command numactl hardware to get an overview of the memory architecture on your machine If this shows you have only one node then there is no advantage to making a NUMA aware build of OOMMF The next step is to edit the config platforms for your platform For example on a 64 bit Linux box this file is config platforms linux x86_64 tcl In the section labeled LOCAL CONFIGURATION find the line 12 config SetValue use_numa 1 Edit this to remove the leading character Alternatively and actually preferably create a local subdirectory and make a local configuration file with the same platform name e g config platforms local linux x86_64 tcl on a 64 bit Linux machine Add the line config SetValue use_numa 1 to this file The advantage of using a config platforms local file is that you can make changes without modifying the original OOMMF source code which makes it easier to port your local changes to future releases of OOMMF If this is done correctly then the command tclsh oommf tcl platform will show that NUMA support is enabled Then simply run tclsh oommf tcl pimake distclean and tclsh oommf tcl pimake from the OOMMF root directory to build a NUMA aware version of OOMMF To activate
102. Whether to register with the account service directory application so that mmLaunch Sec 6 can provide an interactive interface Default 1 do register which will automatically start account service directory and host service directory applications as necessary start_paused Pause solver after loading problem end paused Pause solver and enter event loop at bottom of batchsolve tcl rather than just falling off the end the effect of which will depend on whether or not Tk is loaded restart lt 0 1 gt Determines solver behavior when a new problem is loaded If 1 then the solver will look for basename log and basename omf files to restart a previous run from the last saved state where basename is the Base Output Filename specified in the input problem specification If these files cannot be found then a warning is 114 issued and the solver falls back to the default behavior equivalent to restart 0 of starting the problem from scratch The specified restart setting holds for all problems fed to the solver not just the first file Immediately load and run the specified MIF 1 x file The input file file should contain a Micromagnetic Input Format Sec 17 1 x problem description such as produced by mmProbEd Sec 8 The batch solver searches several directories for this file including the current working directory the data and scripts sub directories and parallel directories relative to the directories app mmsolv
103. Windows platforms the Suffixes field is labeled File Extension and only one file extension may be entered Files downloaded from a web server are handled according to their MIME Type rather than their file extension so that restriction isn t important when web browsing If you wish to have files on the local disk with all the above file extensions 145 array set plot_config arrow status 1 arrow autosample 1 arrow subsample 0 arrow colormap Red Black Blue arrow colorcount 256 arrow quantity Z arrow colorreverse 0 arrow colorphase 0 arrow size 1 pixel status 0 pixel autosample 1 pixel subsample 0 pixel colormap Blue White Red pixel colorcount 256 pixel quantity pixel colorreverse pixel colorphase pixel size pixel opaque Fr OO array set print_config orient paper hpos vpos units landscape letter center center in misc background misc drawboundary misc boundarycolor misc boundarywidth misc margin misc defaultwindowwidth misc defaultwindowheight misc width misc height misc rotation misc zoom misc datascale misc relcenterpt viewaxis viewaxis xarrowspan viewaxis xpixelspan viewaxis yarrowspan viewaxis ypixelspan viewaxis Zarrowspan viewaxis zpixelspan tmargin lmargin pwidth pheight croptoview 1 NOR oOo OO CO 0 5 white black 10 640 480 o0oo0oo0oo0oo oO 5 0 5 Figure 4 Contents of default configuration file
104. __ in above init_script regsub all __SKIP_COUNT__ init_script SKIP_COUNT init_script TaskInfo SetSlaveInitScript init_script Form task list TaskInfo AppendTask A BatchTaskRun taskA mif TaskInfo AppendTask B BatchTaskRun taskB mif TaskInfo AppendTask C BatchTaskRun taskC mif Figure 2 Task script with iteration output octrltask tcl 123 value 10e 13 is passed on by BatchTaskRun to the SolverTaskInit proc which has been redefined to process this argument as the value for A as described above There are 6 tasks in all and 3 slave processes so the first three tasks will run concurrently in the 3 slaves As each slave finishes it will be given the next task until all the tasks are complete FILE multitask tcl This is a sample batch task file Usage example tclsh oommf tcl batchmaster multitask tcl hostname port Task script configuration set RMT_MACHINE foo set RMT_TCLSH tclsh set RMT_OOMMF path to oommf oommf tcl set RMT_WORK_DIR path to oommf app mmsolve data set BASEMIF taskA set A_list 10e 13 10e 14 10e 15 10e 16 10e 17 10e 18 Slave launch commands TaskInfo ModifyHostList RMT_MACHINE TaskInfo AppendSlave 2 exec tclsh Zoommf batchslave tk 0 connect_info batchsolve tcl TaskInfo AppendSlave 1 exec rsh RMT_MACHINE cd RMT_WORK_DIR RMT_TCLSH RMT_OOMMF batchslave tk 0 connect_info batchsolve tcl Slave initialization script with batchs
105. a label valueunit kA m valuemultiplier 0 79577472 Multiply data block values by this Valu Valu End eRangeMaxMag eRangeMinMag to get true value in valueunits 1005 3096 These are in data block value units 1e 8 and are used as hints or defaults by postprocessing programs The mmDisp program ignores any points with magnitude smaller than ValueRangeMinMag and uses ValueRangeMaxMag to scale inputs for display Header 224 Anything between End Header and Begin data text Begin data binary 4 or Begin data binary 8 is ignored HH Data input is in x component y component z component triples ordered with x incremented first then y and finally z Begin data text 1000 O O 724 1 0 700 023 578 5 500 4 652 36 lt data omitted for brevity gt 252 34 696 42 671 81 End data text End segment Figure 11 Commented OVF sample file 19 2 The OVF 2 0 format The OVF 2 0 format is a modification to the OVF 1 0 format that also supports fields across three spatial dimensions but having values of arbitrary but fixed dimension In the OVF 2 0 format 1 The first line reads OOMMF OVF 2 0 for both regular and irregular meshes 2 In the Segment Header block the new record valuedim is required This must specify an integer value N bigger or equal to one 3 In the Segment H
106. a three item list representing the three components of the vector field at the specified point GetAtlasRegions This command takes one argument which is a reference to an atlas and returns an ordered list of all the regions in that atlas The first item on the returned list will always be universe which includes all points not in any of the other regions including in particular any points outside the nominal bounds of the atlas Sample usage set regions_list GetAtlasRegions atlas GetAtlasRegionByPosition This command takes four arguments a reference to atlas followed by the x y and z coordinates of a point using problem coordinates i e meters The return value is the name of the region containing the specified point This name will match exactly one of the names on the list returned by the GetAtlasRegions command for the given atlas Note that the return value might be the universe region Sample usage set rogue_region GetAtlasRegionByPosition atlas 350e 9 120e 9 7 5e 9 17 2 3 Sample MIF 2 2 File MIF 2 2 HEHHHHHHEHHHHHH Constants set pi expr 4 atan 1 0 set mu0 expr 4 pixte 7 HHHHHHHHHHHHHHH Command line controls Parameter seed 1 Parameter thickness 6e 9 Parameter stop 1e 2 Texturing angle phideg in degrees from 0 to 90 O is all z Parameter phideg 10 HEHHHHHHHHHHHEH Output options SetOptions subst 204 basename polyuniaxial_phi_ phideg scalar_output_format 1
107. ain text file You may need to edit this file to add or modify entries 3 Edit oommf config platforms wintel tcl At a minimum you will have to change the program_compiler_ct value to point to the Borland C compiler The sample wintel tcl file assumes the librarian tlib and the linker ilink32 are in the execution path and that the Borland compatible import libraries with names as specified above are in the Tcl Tk library directory If this is not the case then you will have to make appropriate modifications Also you may need to add the o switch to the linker command to force ordinal usage of the Borland compatible Tcl Tk libraries produced in the previous step After this continue with the instructions in Sec 2 2 3 Compiling and Linking Using Digital Mars C The Digital Mars C command line compilers dmc versions 8 50 and earlier do not successfully build this release of OOMMF The following notes may help build OOMMF with a later release of dmc 1 Install the Digital Mars C compiler tools and STL Unpack the dmc archive into a convenient location The default name for the root directory of the dmc installation area is dm Unpack the STLport C Standard Library into the dmc installation area The top level directory in the STLport archive is dm so if you unzip this archive from the parent directory to the dmc installation area it will naturally unpack into its standard location Then modify the dmc
108. an op tional parameter cache_grid which takes a mesh specification that describes the grid used for cache spatial discretization If cache_grid is not specified then each call to Oxs_RandomVectorField generates a different field If you want to use the same random vector field in two places as a base for setting say anisotropy axes and ini tial magnetization then specify cache_grid with the appropriate usually the base problem mesh Examples diskarray mif sample2 mif randomshape mif stdprob1 mif Oxs_PlaneRandomVectorField Similar to Oxs_RandomVectorField except that sam ples are drawn from 2D planes rather than 3 space The Specify block has the form Specify Oxs_RandomVectorField name plane_normal vector_field_spec minnorm minvalue max norm mazvalue cache grid mesh_spec The min norm max norm and cache grid parameters have the same meaning as for the Oxs_RandomVectorField class The additional parameter plane_normal specifies a vector field that at each point provides a vector that is orthogonal to the plane from which the random vector at that point is to be drawn If the vector field is specified explicitly as three real values then a spatially uniform vector field is produced and all the random vectors will lie in the same plane More generally however the normal vectors and associated planes may vary from point to point As a special case if a normal vector at a point is the zero vector then no planar restri
109. analogue to this class is Oxs_AtlasVectorField which is described below in the vector fields portion of this section Examples diskarray mif ellipsoid mif grill mif spinvalve mif tclshapes mif Oxs_LinearScalarField Returns a value that varies linearly with position The Specify block has the form Specify Oxs_LinearScalarField name norm value vector Us Vy vz offset off If optional value norm is specified then the given vector is first scaled to the requested size The offset entry is optional with default value 0 For any given point x y z the scalar value returned by this object will be xvz yvy zv of f Example spinvalve af mif Oxs_RandomScalarField Defines a scalar field that varies spatially in a random fashion The Specify block has the form Specify Oxs_RandomScalarField name range min minvalue range_max mazvalue cache grid mesh_spec The value at each position is drawn uniformly from the range declared by the two re quired parameters range min and range max There is also an optional parameter cache_grid which takes a mesh specification that describes the grid used for spatial discretization If cache_grid is not specified then each call to Oxs_RandomScalarField generates a different field If you want to use the same random scalar field in two places as a base for setting say anisotropy coefficients and saturation magnetization then specify cache_grid with the appropriate usually
110. and xnodes ynodes znodes e pointcount Number of data sample points locations i e nodes integer For irreg ular grids only e xbase ybase zbase Three separate lines denoting the position of the first point in the data section in units of meshunit For rectangular grids only e xstepsize ystepsize zstepsize Three separate lines specifying the distance be tween adjacent grid points in units of meshunit Required for rectangular grids but may be specified as a display hint for irregular grids e xnodes ynodes znodes Three separate lines specifying the number of nodes along each axis integers For rectangular grids only 19 1 2 Data block The data block start is marked by a line of the form Begin data lt representation gt 222 where lt representation gt is one of text binary 4 or binary 8 Text mode uses the ASCII specification with individual data items separated by an arbitrary amount of whitespace spaces tabs and newlines Comments are not allowed inside binary mode data blocks but are permitted inside text data blocks The binary representations are IEEE floating point in network byte order MSB To insure that the byte order is correct and to provide a partial check that the file hasn t been sent through a non 8 bit clean channel the first datum is a predefined value 1234567 0 Hex 49 96 B4 38 for 4 byte mode and 123456789012345 0 Hex 42 DC 12 21 83 7
111. aratory steps are necessary before building OOMMF with this compiler 1 Properly complete bcc55 compiler installation Be sure to read the readme txt file in the BCC55 subdirectory of the Borland install directory In particular check that the bcc32 cfg and ilink32 cfg configuration files exist in the BIN subdirectory and have appropriate contents If you omit this step you will get error messages during the OOMMF build process relating to the inability of the Borland compiler to find system header files and libraries You will probably also need to add the Borland BIN directory to your PATH environment variable Some of the Borland tools are fragile with respect to spaces in their pathnames so you should either select the Borland install directory to be one without spaces anywhere in the pathname e g use C Borland instead of C Program Files Borland or at least when setting the PATH use the 8dot3 style short name version of each component of the Borland install directory e g PATH C Progra 1 Borland BCC55 Bin PATH Use dir x to display both the short and long versions of filenames The Borland Developer Studio 2006 install automatically sets the path to include the long name version of the Borland BIN directory you should manually change this via the System dialog box from the Control Panel Select the Advanced tab and pull up the Environ ment Variables sub dialog Edit the Path variable as discussed above chec
112. ard setting is 15136 pid Specify application instance to nickname by system PID process identifier rather than OID OOMMF identifier timeout secs Maximum time to wait for response from servers in seconds Default is five seconds oid The OOMMF ID of the running application instance to nickname unless the pid option is specified in which case the system PID is specified instead nickname One or more nicknames to associate with the specified application instance Each nickname must include at least one non numeric character This command is used to associate nicknames with running instances of OOMMEF applica tions The MIF 2 1 Destination command can then use the nickname to link Oxs output to a given OOMMEF application instance at problem load time Nicknames for GUI applications can be viewed in the application About dialog box or can be seen for any application via the names option to the command line application pidinfo 16 15 Platform Independent Make pimake The application pimake is similar in operation to the Unix utility program make but it is written entirely in Tcl so that it will run anywhere Tcl is installed Like make pimake controls the building of one file the target from other files Just as make is controlled by rules in files named Makefile or makefile pimake is controlled by rules in files named makerules tcl 176 Launching The pimake launch command is tclsh oommf tcl pimake standard options
113. arization direction 7 PA A 1 A m m e secondary spin tranfer term 71 In the definition of 8 e is the electron charge in C J is current density in A m t is the free layer thickness in meters and M is the saturation magnetization in A m The various parameters are defined in the Specify block which is an extension of that for the Oxs_RungeKuttaEvolve class Specify Oxs SpinXferEvolve name alpha a gamma_LL 7 gamma_G y do_precess precess allow signed gamma signed gamma min timestep minimum_stepsize max_timestep mazimum_stepsize fixed_spins atlas_spec region region start dm Am stage_start scontinuity error_rate rate absolute_step_error abs_error relative step_error rel_error energy precision eprecision min_step_headroom min_headroom max_step_headroom maz_headroom reject_goal reject_proportion method subtype P polarization P_fixed p_fixed_layer P_free p_free_layer Lambda A Lambda_fixed A_fixed_layer Lambda free A_free_layer eps_prime ep J current_density J_profile Jprofile_script J profile args Jprofile_script_args mp p_direction energy slack eslack The options duplicated in the O0xs_RungeKuttaEvolve class Specify block have the same meaning and default values here with the exception of error_rate which for f2 Oxs_SpinXferEvolve has the default value of 1 i e disabled The default values for P and Lambda are 0 4 and 2 respectively If preferred values for the
114. ase pixel colorinvert pixel autosample pixel subsample pixel size e OoOrOOM M e array set print_config orient paper hpos vpos units landscape letter center center in misc background misc drawboundary misc boundarywidth misc boundarycolor misc boundarypos misc matwidth misc matcolor misc margin misc width misc height misc crop misc zoom misc rotation misc datascale misc relcenterpt 0 viewaxis viewaxis xarrowspan viewaxis xpixelspan viewaxis yarrowspan viewaxis ypixelspan viewaxis Zarrowspan viewaxis zpixelspan tmargin 1 lmargin 1 pwidth 6 pheight 6 croptoview 1 oOoOO Oo FFFFFF 1 1 000000 front 0 FFFFFF 10 640 0 5 0 5 Figure 6 Contents of default configuration file avf2ps config 168 Launching The crc32 command line is tclsh oommf tcl crc32 standard options binary text decimal hex v level file where binary text Select binary default or text input mode decimal hex Output CRC value in decimal default or hexadecimal format v level Verbosity informational message level with 0 generating only error messages and minimal CRC output and larger numbers generating additional information The level value is an integer defaulting to 1 file List of files to process If no files are listed then input is read from stdin For each file in the input file list the CRC 32 is computed and output By default the
115. ass and the same default values except for relative_step_error and error_rate which for Oxs_RungeKuttaEvolve have the default values of 0 01 and 1 0 respectively Additionally the alpha gamma_LL and gamma_G options may be initialized using scalar field objects to allow these material parameters to vary spatially The allow_signed_ gamma parameter is for simulation testing purposes and is in tended for advanced use only There is some lack of consistency in the literature with respect to the sign of y For this reason the Landau Lifshitz Gilbert equations are presented above 2 3 using the absolute value of y This is the interpretation used if allow_signed_gamma is 0 the default If instead allow_signed_gamma is set to 1 then the Landau Lifshitz Gilbert equations are interpreted without the absolute val ues and with a sign change on the y terms i e the default value for y in this case is 2 211 x 10 units are m A s In this setting if y is set positive then the spins will precess backwards about the effective field and the damping term will force the spins away from the effective field and increase the total energy If you are experimenting with y gt 0 you should either set a lt 0 to force spins back towards the effective field or disable the energy precision control discussed below The two controls min step headroom default value 0 33 and max_step_ headroom default value 0 95 replace the single step_headroom optio
116. at either tclsh or wish is a suitable interpreter This means that simply double clicking on an icon associated with the file oommf tcl say in Windows Explorer will launch the bootstrap application with no arguments This will result in the default behavior of launching the application mmLaunch which is suitable for launching other OOMMF applications If this doesn t work refer back to the Windows Options section in the installation instructions Sec 2 4 2 31 6 OOMMEF Launcher Control Interface mmLaunch localhost W donahue donahue Programs Threads mm rchive mmDisp lt 3 gt mmDataTable lt 4 gt mmGraph lt 5 gt mm Disp Oxsii lt 6 gt J mmGraph lt 7 gt mmDataTable mmGraph mm ProbEd mmSolve2D Oxsii Overview The application mmLaunch launches monitors and controls other OOMMEF applications It is the OOMMEF application which is most closely connected to the account service directory and host service directory applications that run behind the scenes It also provides user interfaces to any applications notably Oxsii Sec 7 1 and mmSolve2D Sec 10 1 that do not have their own user interface window Launching mmLaunch should be launched using the bootstrap application Sec 5 The command line is tclsh oommf tcl mmLaunch standard options Controls Upon startup mmLaunch displays a panel of checkbuttons one for each host service directory to which it is connected In the current release of
117. at menu command brings up a Format dialog box to change the justification and format specification string The latter is the conversion string passed to the Tcl format command which uses the C printf format codes If the Adjust Selected radiobutton is active then the specification will be applied to only the currently selected highlighted data values Alternately if Adjust All is active then the specification will be applied to all data values and will additionally become the default specification A right mouse button click on a display entry will select that entry and bring up the Format dialog box with the justification and format specifications of the selected entry These specifications with any revisions may then be applied to all of the selected entries 127 If a value cannot be displayed with the selected format specification string e g if a Yd integer format were applied to a string containing a decimal point then the value will be printed in red in the form as received by mmDataTable without any additional formatting The menu selection File Reset reinitializes the mmDataTable application to its original state clearing the display and the Data menu The reset operation is also automatically invoked upon receipt of new data following a data set close message from a solver application The menu selection File Exit terminates the application The menu Help provides the usual help facilities 128 12 Data Graph Di
118. ation as described above If onefile is not requested then as each input file is processed a name for the corre sponding output file is produced from the input filename by rules determined by handing the opatexp and opatsub expressions to the Tcl regsub command Refer to the Tcl regsub documentation for details but essentially whatever portion of the input filename is matched by the opatexp expression is removed and replaced by the opatsub string The default opatexp expression matches against any filename extension of up to 3 characters and the default opatsub string replaces this with the extension odt 16 3 Vector Field File Format Conversion avf2ovf The avf2ovf program converts vector field files from any of the recognized formats OVF VIO see Sec 19 into the OVF 1 0 format Launching The avf2ovf launch command is tclsh oommf tcl avf2ovf standard options clip xmin ymin zmin xmax ymax zmax flip flipstr format lt text b4 b8 gt grid lt rect irreg gt info keepbb mag pertran xoff yoff zoff q rpertran rxoff ryoff rzoff subsample period infile outfile where clip xmin ymin zmin xmax ymax zmax The 6 arguments specify the vertices of a bounding clip box Only mesh points inside the clip box are brought over into the output file Any of the arguments may be set to to use the corresponding value from the input file i e to not clip along that box face 158 fli
119. ats mmProbEd also acts as a server supplying problem descriptions to running mmSolve2D micromagnetic solvers Launching mmProbEd may be started either by selecting the mmProbEd button on mmLaunch or from the command line via tclsh oommf tcl mmProbEd standard options net lt 0 1 gt net lt 0 1 gt Disable or enable a server which provides problem descriptions to other appli cations By default the server is enabled When the server is disabled mmProbEd is only useful for editing problem descriptions and saving them to files Inputs The menu selection File Open displays a dialog box for selecting a file from which to load a MIF problem description Several example files are included in the OOMMF release 102 Cancel Damp Coef io 5 Dir x i A 2 oc Dir 2 DE a T in the directory oommf app mmpe examples At startup mmProbEd loads the problem contained in ocommf app mmpe init mif as an initial problem Note When loading a file mmProbEd discards comments and moves records it does not understand to the bottom of its output file Use the FileSource application Sec 9 to serve unmodified problem descriptions Outputs The menu selection File Save as displays a dialog box for selecting entering a file in which the problem description currently held by mmProbEd is to be saved Because the internal data format use by mmProbEd is an unordered array that does not include comments or unrecognized records the
120. being defined The regionname label specifies the name assigned to the region contained in the atlas The name entry is optional if not specified then the region name is taken from the object instance name i e atlasname Examples sample mif cgtest mif Oxs_ImageAtlas This class is designed to allow an image file to be used to define re gions in terms of colors in the image It is intended for use in conjunction with the Oxs_AtlasScalarField and Oxs_AtlasVectorField classes in circumstances where a small number of distinct species materials are being modeled This provides a generalization of the mask file functionality of the 2D solver Sec 17 3 3 46 For situations requiring continuous variation in material parameters the script field classes should be used in conjunction with the ReadFile MIF extension command See the ColorField sample proc in the ReadFile documentation in Sec 17 1 2 for an example of this technique The Oxs_ImageAtlas Specify block has the following form Specify Oxs_ImageAtlas name xrange rmin zmar yrange ymin ymax zrange zmin zmar viewplane view image pic colormap color 1 region_name color 2 region_name color n region_name matcherror maz_color_distance The xrange yrange zrange entries specify the extent of the atlas in meters The viewplane view value should be one of the three two letter codes xy zx or yz which specify the mapping of the horizontal and vertical axes
121. ber of pixels per vector in the fully sampled vector field This value is not affected by the subsampling rate The Margin entry specifies the margin size in pixels to be maintained around the vector field The next row of entry boxes control slice display Slice selection allows display of that subset of the data that is within a specified distance of a plane running perpendicular to the view axis The location of that plane with respect to the view axis is specified in the X slice center Y slice center or Z slice center entry depending on the current view axis The thickness of the slice may be varied separately for arrow and pixel displays as specified in the next two entry boxes The slice span boxes interpret specially the following values 0 resets the slice thickness to the default value which is usually the thickness of a single cell Any negative value sets the slice thickness to be the full thickness of the mesh Values for all of the slice control entries are specified in the fundamental mesh spatial unit for example 138 meters Refer to the vector field file format Sec 19 documentation for more on mesh spatial units Below the slice contols are controls to specify whether or not a bounding polygon is displayed and the background color for the display window No changes made by the user in the Options Configure dialog box affect the display window until either the Apply or OK button is selected If the OK button is se
122. can be found in the directory oommf app oxs examples This section describes the Oxs_Ext classes available in the standard OOMMF distribution including documentation of their Specify block initialization strings and a list of some sample MIF files from the oommf app oxs examples directory that use the class The standard Oxs_Ext objects i e those that are distributed with OOMMF can be identified by the Oxs prefix in their names Additional Oxs_Ext classes may be available on your system Check local documentation for details In the following presentation the Oxs_Ext classes are organized into 8 categories atlases meshes energies evolvers drivers scalar field objects vector field objects and MIF support classes The following Oxs_Ext classes are currently available e Atlases Oxs_BoxAtlas Oxs_ImageAtlas Oxs_MultiAtlas Oxs_ScriptAtlas Oxs_EllipsoidAtlas e Meshes Oxs_RectangularMesh e Energies Oxs_CubicAnisotropy Oxs_Demag Oxs_Exchange6Ngbr Oxs_ExchangePtwise Oxs_FixedZeeman Oxs_RandomSiteExchange Oxs_ScriptUZeeman Oxs_SimpleDemag Oxs_StageZeeman Oxs_TransformZeeman Oxs_TwoSurfaceExchange Oxs_UniaxialAnisotropy Oxs_UniformExchange Oxs_UZeeman e Evolvers Oxs_CGEvolve Oxs_EulerEvolve Oxs_RungeKuttaEvolve Oxs_SpinxferEvolve e Drivers Oxs_MinDriver Oxs_TimeDriver e Scalar Field Objects Oxs_AtlasScalarField Oxs_LinearScalarField Oxs_RandomScalarField Oxs_ScriptScalarField Oxs_UniformScalarField Oxs_VecMagScalarField Oxs_Scr
123. ch as exchange energy magnetostatic fields and anisotropy energies Material parameters such as the anisotropy constant K1 and the ex change constant A are generally specified inside the Specify block for the relevant energy e g Oxs_UniaxialAnisotropy or Oxs_Exchange6Ngbr The exception to this is saturation magnetization Ms which is declared in the driver Specify block The initial magnetization m0 is also specified in the driver Specify block In many cases these material parameters may be varied spatially by defining them using scalar or vector field objects Sec 7 3 6 page 82 As discussed in the section on Specify Conventions Sec 17 1 3 auxiliary ob jects such as scalar and vector fields can be defined either inline i e inside the body of the referencing Specify block or in their own standalone top level Specify blocks In the latter case the auxiliary Specify blocks must precede the referencing Specify blocks in the MIF 2 1 file Given the energies and fields the evolver and driver form a matched pair that ad vance the magnetic state from an initial configuration obeying either Landau Lifshitz Gilbert LLG dynamics or direct energy minimization For energy minimization stud ies the driver must be an Oxs_MinDriver object and the evolver must be a minimization evolver At the time of this writing the only minimization evolver packaged with OOMMF is the Oxs_CGEvolve conjugate gradient evolver For time evolution LLG si
124. ching procedure in this case is not defined Examples imageatlas mif grill mif Oxs MultiAtlas This atlas is built up as an ordered list of other atlases The set of regions defined by the Oxs_MultiAtlas is the union of the regions of all the atlases contained therein The sub atlases need not be disjoint however each point is assigned to the region in the first sub atlas in the list that contains it so the regions defined by the Oxs_MultiAtlas are effectively disjoint 49 The Oxs_MultiAtlas specify block has the form Specify Oxs_MultiAtlas name atlas atlas_1_spec atlas atlas_2_spec xrange smin zmar yrange ymin ymaz zrange zmin zmax Each atlas_spec may be either a reference to an atlas defined earlier and outside the current Specify block or else an inline embedded atlas definition The bounding box xrange yrange and zrange specifications are each optional If not specified the corresponding range for the atlas bounding box is taken from the minimal bounding box containing all the sub atlases If the atlases are not disjoint then the regions as defined by an Oxs_MultiAtlas can be somewhat different from those of the individual component atlases For example suppose regionA is a rectangular region in atlasA with corner points 5 5 0 and 10 10 10 and regionB is a rectangular region in atlasB with corner points 0 0 0 and 10 10 10 When composed in the order atlasA atlasB inside an Oxs MultiAtlas r
125. class does not include any oersted field arising from the current Of course arbitrary fields simulating the oersted field may be added separately as Zeeman energy terms An example of this is contained in the spinxfer mif sample file There are no temperature effects in this evolver i e it is a T 0 K code Note also that m is fixed For basic usage the Specify block can be as simple as Specify Oxs_SpinXferEvolve evolve alpha 0 014 J 7 5e12 mp 1 0 0 P 0 4 Lambda 2 This class is still in early development at this time the example files are located in oommf app oxs local instead of oommf app oxs examples Examples spinxfer mif spinxfer miltat mif spinxfer onespin mif 73 Oxs_CGEvolve The minimization evolver is Oxs_CGEvolve which is an in development conjugate gradient minimizer with no preconditioning The Specify block has the form Specify Oxs_CGEvolve name gradient_reset_angle reset_angle gradient_reset_count count minimum bracket_step minbrack maximum_bracket_step maxbrack line minimum_angle_precision min_prec_angle line minimum_relwidth relwidth energy precision eprecision method cgmethod fixed_spins atlas_spec region region All entries have default values The evolution to an energy minimum precedes by a sequence of line minimizations Each line represents a one dimensional affine subspace in the 3N dimensional space of possible magnetization configurations where N is the numb
126. comment You can put anything you want on comment lines Columns Iteration Applied Field Total Energy Mx Units mT J m 3 A m 103 50 0 00636 787840 1000 32 0 00603 781120 10300 5000 0 00640 800e3 Table End Figure 10 Sample ODT file field file format used by both the 2D Sec 10 and 3D Sec 7 micromagnetic solvers It is also the input data type read by mmDisp Sec 13 There are three versions of the OVF format supported by OOMMF The OVF 1 0 and 2 0 formats are preferred formats and the only ones written by OOMME software They support both rectangular and irregular meshes in binary and ASCII text The OVF 0 0 format formerly SVF is an older simpler format that can be useful for importing three dimensional vector field data into OOMMF from other programs A fourth format the VecFil or Vector Input Output VIO format was used by some precursors to the OOMMF code Although OOMMF is able to read the VIO format its use is deprecated In all these formats the field domain i e the spatial extent lies across three dimensions with units typically expressed in meters or nanometers In all the formats except the OVF 2 0 format the field values are also three dimensional the value units are more varied but are most often Tesla or A m The OVF 2 0 format is more general in that the field values can be of any arbitrary dimension N gt 0 This dimension however is fixed within the file If N 3 then
127. comments data or any of the following 5 recognized descriptor tag lines e Table Start Optional used to segment a file containing multiple data table blocks Anything after the colon is taken as an optional label for the following data block Title Optional everything after the colon is interpreted as a title for the table e Columns Required One parameter per column designating the label for that column Spaces may be embedded in a column label by using the normal Tcl grouping mechanisms i e double quotes and braces Units Optional If given it should have one parameter for each column giving a unit label for the corresponding column Table End Optional no parameters Should be paired with a corresponding Table Start record Data may appear anywhere after the Columns descriptor record and before any Table End line with one record per line The data should be numeric values separated by whitespace The two character open close curly brace pair is used to indicate a missing value The command line utility odtcols Sec 16 12 can be a useful tool for examining and partitioning ODT files 19 Vector Field File Format OVF Vector field files specify vector quantities e g magnetization or magnetic flux density as a function of spatial position The OOMMF Vector Field OVF format is the output vector 219 ODT 1 0 Table Start Title This is a small sample ODT file This is a sample
128. consist of a Record Identifier followed by a parameter list The Record Identifier is separated from the parameter list by one or more and or characters Whitespace and case is ignored in the Record Identifier field The parameter list must be a proper Tcl list The parameters are parsed broken into separate elements following normal Tcl rules in short items are separated by whitespace except as grouped by double quotes and curly braces Opening braces and quotes must be whitespace separated from the preceding text The grouping characters are removed during parsing Any character that is found outside of any grouping mechanism is interpreted as a comment start character The and all following characters on that line are interpreted as a comment Order of the records in a MIF 1 1 file is unimportant except as explicitly stated below If two or more lines contain the same Record Identifier then the last one takes precedence with the exception of Field Range records of which there may be several active All records are required unless listed as optional Some of these record types are not supported by mmProbEd however you may modify a MIF 1 1 file using any plain text editor and supply it to mmSolve2D Sec 10 1 using FileSource Sec 9 For convenience the Record Identifier tags are organized into several groups these groups correspond to the top level buttons presented by mmProbEd We follow this convention below S
129. cription server is selected when the LoadProblem 110 button is invoked nothing will happen The Reset button operates similarly except that the current problem specifications are used Once a problem is loaded the solver can be put into any of three states run relax and pause Selecting Relax puts the solver into the relax state where it runs until a control point is reached after which the solver pauses If the Relax button is reselected after reaching a control point then the solver will simply re pause immediately The Field or Field button must be invoked to change the applied field state Field state schedules are discussed below The Run selection differs in that when a control point is reached the solver automatically steps the nominal applied field to the next value and continues In run mode the solver will continue to process until there are no more applied field states in the problem description At any time the Pause button may be selected to pause the solver The solver will stay in this state until the user reselects either Run or Relax The current state of the solver is indicated in the Status line in the center panel of the user interface window The problem description MIF 1 x format specifies a fixed applied field schedule see Sec 17 3 5 This schedule defines an ordered list of applied fields which the solver in run mode steps through in sequence The Field and Field buttons allow the user
130. ction is made and the resulting random vector is drawn uniformly from a hollow ball in three space satisfying the minimum maximum norm constraints Example sample2 mif Oxs_ScriptOrient VectorField This class is analogous to the Oxs_ScriptOrientScalarField class page 88 The Specify block has the form Specify Oxs_ScriptOrientVectorField name field vector_field_spec script Tcl_script script_args args_request atlas atlas_spec xrange rmin zmar yrange ymin ymax zrange zmin zmar 96 The interpretation of the specify block and the operation of the Tcl script is exactly the same as for the Oxs_ScriptOrientScalarField class except the input field and the resulting field are vector fields instead of scalar fields Note that the orientation transformation is applied to the import spatial coordinates only not the output vector For example if the field value represents a shaped vector field and the script proc is a rotation transformation then the resulting vector field shape will be rotated as compared to the original vector field but the output vectors themselves will still point in their original directions In such cases one may wish to compose the Oxs_ScriptOrientVectorField with a Oxs_ScriptVectorField object page 93 to rotate the output vectors as well This situation occurs also with the Oxs_AffineOrientVectorField class See the Oxs_AffineTransformVectorField class documentation page 97 for an example i
131. ctions which follow the OOMMF applications are described in terms of the services they provide and the services they require 28 5 Command Line Launching Some of the OOMMF applications are platform independent Tcl scripts Some of them are Tcl scripts that require special platform dependent interpreters Others are platform dependent compiled C applications It is likely that some of them will change status in later releases of OOMMF Each of these types of application requires a different command line for launching Rather than require all OOMMF users to manage this complexity we provide a pair of programs that provide simplified interfaces for launching OOMMEF applications The first of these is used to launch OOMMEF applications from the command line Because its function is only to start another program we refer to this program as the bootstrap application The bootstrap application is the Tcl script oommf tcl In its simplest usage it takes a single argument on the command line the name of the application to launch For example to launch mmGraph Sec 12 the command line is tclsh oommf tcl mmGraph The search for an application matching the name is case insensitive Here as elsewhere in this document the current working directory is assumed to be the OOMMF root directory For other cases adjust the pathname to oommf tcl as appropriate As discussed in Sec 2 1 the name of the Tcl shell rendered here as tclsh may va
132. cussed next 201 4 Two new top level extension commands are supported in the MIF 2 2 format EvalScalarField and EvalVectorField These commands are described in detail below 17 2 2 MIF 2 2 New Extension Commands In addition to the commands available in MIF 2 1 files Sec 17 1 2 MIF 2 2 introduces the following new commands GetMifFilename GetMifParameters GetOptions SetOptions EvalScalarField EvalVectorField GetAtlasRegions and GetAtlasRegionByPosition GetMifFilename The GetMifFilename command returns the full absolute name of the MIF file being read This command takes no parameters GetMifParameters This command takes no parameters and returns an even numbered list of Parameter label value pairs as set on the command line or in the Load Problem dialog box If no parameters were specified then the return will be an empty list GetOptions The GetOptions command takes no parameters It returns the accumulated contents of all preceding SetOptions blocks as an even numbered list of label value pairs SetOptions In MIF 2 1 files the output basename and output file formats are specified inside the driver s Specify block In MIF 2 2 these specifications are moved to a sep arate SetOptions block This block can be placed anywhere in the MIF file but is typically placed near the start of the file so that it affects all output initializations The SetOptions command takes a single argument which is a list of label
133. d Installation Sec 2 3 pertaining to your compiler 2 When compiling Sec 2 2 3 there is an error something like lt 30654 gt pimake 1 x x x MakeRule panic Don t know how to make usr include tcl h This means the header file tcl h is missing from your Tcl installation Other missing header files might be tk h from the Tk installation or Xlib h from an X Window System installation on Unix In order to compile OOMMF you need to have the development versions of Tcl Tk and if needed X installed The way to achieve that is platform dependent On Windows you do not need an X installation but when you install Tcl Tk be sure to request a full installation or one with header and library files On Linux be sure to install developer packages for example the XFree86 devel RPM as well as user packages Other platforms are unlikely to have this problem In the case of Xlib h it is also possible that the tkConfig sh file has an incorrect entry for TK_XINCLUDES A workaround for this is to add the following line to your oommf config platforms platform file 230 config SetValue TK_XINCLUDES I usr X11R6 include Adjust the include directory as appropriate for your system When compiling Sec 2 2 3 there is an error indicating that exceptions are not sup ported Parts of OOMMF are written in C and exceptions have been part of the C language for many years If your compiler does not support them it is
134. d with certain restrictions by the mmSolve 2D solvers as well The mmProbEd problem editor can read and write this format The mifconvert Sec 16 11 command line tool can be used to convert between the MIF 1 1 and MIF 1 2 formats and to convert from the MIF 1 x formats to the Oxs MIF 2 1 format mifconvert is also called automatically by Oxs solvers when a MIF 1 x file is input to them so questions about the details of Oxs interpretation of MIF 1 x files can be answered by running mifconvert separately on the input MIF 1 x file There are four differences between the MIF 1 1 and 1 2 formats In the MIF 1 2 format 1 The first line reads MIF 1 2 2 The Cel1Size record takes three parameters x dimension y dimension and z dimension in meters 3 The 3dSlab 2dSlab 3dCharge and FastPipe parameters of the DemagType record are deprecated 4 The new record SolverType is introduced Valid values are Euler RK2 RK4 RKF54 and CG requesting a first order Euler second order Runge Kutta fourth order Runge Kutta fifth fourth order Runge Kutta Fehlberg and Conjugate Gradient solvers respectively This record is optional with default value of RKF54 If the Cel1Size record has only one parameter then it is interpreted in the same manner as in the MIF 1 1 format i e the parameter is taken as the z and y dimension of the computation cell and the z dimension is set to the part thickness The mmSolve 2D solvers will accept files
135. d directly by Oxsii e The status line in the Oxsii interface window will indicate the problem is loading e When the problem is fully loaded the status line will show Pause and the top row of buttons Reload Reset will become active Also the Output list will fill with available outputs e Set up scheduled outputs For each desired output 1 Select the source from the Output list 2 Select the receiver from the Destination list 3 Specify the frequency of update Step fill in number and check the box Stage fill in number and check the box The items in the Output list will vary depending on the problem that was loaded The items in the Destination list reflect the OOMMF data display and archiving programs currently running Start calculation e On the Oxsii window start the calculation with Run Relax or Step e If you requested mmDataTable output check the boxes for the desired quantities on the mmDataTable window under the Data menu so that they appear and are updated as requested in your schedule e Similarly check the box for the desired X Y1 and Y2 quantities on the mmGraph window s under the X Y1 and Y2 menus Save results 24 e Vector field data magnetization and effective field may be interactively written to disk using mmDisp or may be automatically saved via scheduled output to mmArchive For example to save the magnetization state at the end of each problem stage start up an i
136. d have a nearest neighbor that is on the outside side of the surface A neighbor is determined by the mesh in a typically rectangular mesh each cell has six neighbors In this way 2 discrete lists of cells representing the two surfaces are obtained Each cell from the first list representing surface1 is then matched with the 56 closest cell from the second list i e from surface2 Note the asymmetry in this matching process each cell from the first list is included in exactly one match but there may be cells in the second list that are included in many match pairs or in none If the two surfaces are of different sizes then in practice typically the smaller will be made the first surface because this will usually lead to fewer multiply matched cells but this designation is not required The resulting exchange energy density at cell on one surface from matching cell j on the other is given by ca 1 m mj o2 1 m m Ey J Ai where and o2 respectively are the bilinear and biquadratic surface exchange coefficients between the two surfaces in J m m and m are the normalized unit spins i e magnetization directions at cells i and j and Aj is the discretization cell size in the direction from cell i towards cell 7 in meters Note that if is negative then the surfaces will be anti ferromagnetically coupled Likewise if a2 is negative then the biquadratic term will favor ortho
137. d if a translation filter program is available Client applications that send data to mmDisp control the flow of data The user interacting with the mmDisp window determines how the vector field data are displayed File input is initiated through the File Open dialog box Several example files are included in the OOMMF release in the directory app mmdisp examples When the Browse button is enabled the Open File dialog box will remain open after loading a file so that multiple files may be displayed in sequence The Auto configuration box determines whether the vector subsampling data scale zoom and slice settings should be determined automatically based on the data in the file and the current display window size or whether their values should be held constant while loading the file mm Disp permits local customization allowing for automatic translation from other file formats into one of the vector field formats Sec 19 that mmDisp recognizes When loading a file mmDisp compares the file name to a list of extensions An example extension is gz The assumption is that the extension identifies files containing data in a particular format For each extension in the list there is a corresponding translation program mmDisp calls on that program as a filter which takes data in one format from standard input and writes to standard output the same data in one of the formats supported by mmDisp In its default configuration mmDisp recogniz
138. d part due to crystalline and surface anisotropies e Demag Energy J m The component of the average energy density for the mag netically active elements of the simulated part due to self demagnetizing fields e Zeeman Energy J m The component of average energy density for the mag netically active elements of the simulated part due to interaction with the applied field e Max Angle The maximum angle in degrees between the magnetization orientation of any pair of neighboring spins in the grid The neighborhood of a spin is the same as that defined by the exchange energy calculation In addition the solver automatically keeps a log file that records the input problem specifi cation and miscellaneous runtime information The name of this log file is basename log where basename is the Base Output Filename specified in the input problem specification If this file already exists then new entries are appended to the end of the file Controls The middle section of the user interface window contains a series of buttons providing user control over the solver After a problem description server application has been selected the LoadProblem button triggers a fetch of a problem description from the selected server The LoadProblem button may be selected at any time to re load a problem description from the currently selected server After loading a new problem the solver goes automatically into a paused state If no problem des
139. default_A A atlas world A list A_list HHHHHHHHHHHHHHHHEHEHHAHEHEH HEHEHE Zeeman applied field set field 10000 Maximum field in Oe Specify Oxs_UZeeman subst multiplier expr 1 mu0 1e4 field Hrange 000 001 10 HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH Driver and Evolver Specify Oxs_CGEvolve evolve Specify Oxs_MinDriver subst evolver evolve stopping_mxHxm stop mesh mesh Ms Oxs_ScriptScalarField atlas world script_args relpt script Ellipse Ms Joo 208 mO 00 1 H Figure 8 Example MIF 2 2 file 17 3 MIF 1 1 The MIF 1 1 format is an older micromagnetic problem specification format used by the mmSolve 2D solvers It is not compatible with the MIF 2 1 format used by the Oxs 3D solvers However the command line tool mifconvert Sec 16 11 may be used as a con version aid mifconvert is also called automatically by Oxs solvers when a MIF 1 x file is input to them A sample MIF 1 1 file is presented in Fig 9 The first line of a MIF file must be of the form MIF x y where x y represents the format revision number The predecessor MIF 1 0 format was not included in any released version of OOMMF After the format identifier line any line ending in a backslash V is joined to the succeeding line before any other processing is performed Lines beginning with a character are comments and are ignored Blank lines are also ignored All other lines must
140. define the discretization impressed on the simulation There should be exactly one mesh declared in a MIF 2 file The only standard mesh available at present is Specify Oxs_RectangularMesh name cellsize xstep ystep zstep atlas atlas_spec This creates an axes parallel rectangular mesh across the entire space covered by atlas The mesh sample rates along each axis are specified by cellsize in meters The mesh is cell based with the center of the first cell one half step in from the minimal extremal point xmin ymin ymax for atlas_spec The name is commonly set to mesh in which case the mesh object may be referred to by other Oxs_Ext objects by the short name mesh Examples All MIF files contain this class 7 3 3 Energies The following subsections describe the available energy terms In order to be included in the simulation energy and field calculations each energy term must be declared in its own top level Specify block i e energy terms should not be declared inline inside other Oxs_Ext 52 objects There is no limitation on the number of energy terms that may be specified in the input MIF file Many of these terms have spatially varying parameters that are initialized via field_object_spec entries Sec 7 3 6 in their Specify initialization block see Sec 17 1 3 2 Outputs For each magnetization configuration two standard outputs are provided by all energy terms the scalar output Energy which is th
141. dentifies the mesh type and revision While the OVF 1 0 format was under development in earlier OOMMF releases the revision strings 0 99 and 0 0a0 were sometimes recorded on the file type identification line OOMMF treats all of these as synonyms for 1 0 when reading OVF files The remainder of the file is conceptually broken into Segment blocks and each Segment block is composed of a Segment Header block and a Data block Each block begins with a Begin lt block type gt line and ends with a corresponding End lt block type gt line The number of Segment blocks is specified in the Segment count 1 line Currently only 1 segment is allowed This may be changed in the future to allow for multiple vector fields per file This is followed by Begin Segment to start the first segment 19 1 1 Segment Header block The Segment Header block start is marked by the line Begin Header and the end by End Header Everything between these lines should be either comments or one of the following file descriptor lines They are order independent All are required unless otherwise stated Numeric values are floating point values unless integer is explicitly stated e title Long file name or title e desc Description line Optional Use as many as desired Description lines may be displayed by post processing programs unlike comment lines which are ignored by all automated processing 221 e meshuni
142. describes the cell to cell magnetostatic interaction The convolution is eval uated using fast Fourier transform FFT techniques Several kernels are supported these are selected as part of the problem description in MIF 1 x format for details see Sec 17 3 2 Demag specification Each kernel represents a different interpretation of the discrete magne tization The recommended model is ConstMag which assumes the magnetization is constant in each cell and computes the average demagnetization field through the cell using formulae from 15 and 2 The Landau Lifshitz ODE 5 is integrated using a second order predictor corrector tech nique of the Adams type The right side of 5 at the current and previous step is extrapo lated forward in a linear fashion and is integrated across the new time interval to obtain a quadratic prediction for M at the next time step At each stage the spins are renormalized to M before evaluating the energy and effective fields The right side of 5 is evaluated at the predicted M which is then combined with the value at the current step to produce a linear interpolation of dM dt across the new interval This is then integrated to obtain the final estimate of M at the new step The local one step error of this procedure should be O At The step is accepted if the total energy of the system decreases and the maximum error between the predicted and final M is smaller than a nominal value If the step is rejected
143. din Ping He Michael Ho Mansoor B A Jalil Jorg Jorzick Pierre Olivier Jubert Pavel Kabos Michael Kleiber Kristof Lebecki Oliver Lemcke H T Leung David Lewis Sang Ho Lim Yi Liu Van Luu Andy P Manners Damien McGrouther Johan Moulin Wong Lai Mun Edward Myers Andrew Newell Valen tine Novosad Andrew Perrella Angeline Phoa Anil Prabhakar Robert Ravlic Stephen E Russek Renat Sabirianov Zhupei Shi Xiaobo Tan Alexei Temiryazev Alexander Thieme Stephen Thompson Vassilios Tsiantos Pieter Visscher Ruifang Wang Scott L Whitten burg Kong Xiangyang Ming Yan Tan Swee Yong Chengtao Yu Steven A Zielke and Pei Zou If you have bug reports contributed code feature requests or other comments for the OOMMF developers please send them in an e mail message to lt michael donahue nist gov gt Acknowledgement is appreciated if the software is used We recommend citing the fol lowing NIST technical report M J Donahue and D G Porter OOMMF User s Guide Version 1 0 Interagency Report NISTIR 6376 National Institute of Standards and Technology Gaithersburg MD Sept 1999 and optionally include the URL of the OOMMF home page http math nist gov oommf To help us keep our bibliography page current please direct publication information to lt michael donahue nist gov gt 18http math nist gov oommf http math nist gov oommf bibliography html 236 Index account service directory 27 33
144. ding from a file mmGraph will automatically decompress data using the local customization Sec 2 3 2 Nb_InputFilter decompress option to Oc_Option For details see the discussion on file translation in the Inputs section of the mmDisp documentation Sec 13 Curve breaks i e separation of a curve into disjoint segments are recorded in the data storage buffer via curve break records These records are generated whenever a new data table is detected by mmGraph or when requested by the user using the mmGraph Options Break Curves menu option Outputs Unlike mmDataTable mmGraph internally stores the data sent to it These data may be written to disk via the File Save As dialog box If the file specified already exists then mmGraph output is appended to that file The output is in the tabular ODT format described in Sec 18 The data are segmented into separate Table Start Table End blocks across each curve break record By default all data currently held by mmGraph is written but the Save Selected Data option presented in the File Save As dialog box causes the output to be restricted to those curves currently selected for display In either case the graph display limits do not affect the output The save operation writes records that are held by mmGraph at the time the File Save As dialog box OK button is invoked Additionally the Auto Save option in this dialog box may be used to automatically append to the specified
145. e inverse invert_flag inverse_slack slack Because the output from field is a 3 vector the transform defined by M and offset requires M to be a 3x3 matrix and offset to be a 3 vector Thus if v a represents the vector field specified by the field value then the resulting vector field is M v a off M is described by a list of from one to nine entries in exactly the same manner as for the Oxs_AffineOrientVectorField and Oxs_AffineOrientScalarField classes page 90 The interpretation of offset inverse and inverse_slack is also the same In particular if invert_flag is 1 then the resulting vector field is M v a off The following example illustrates combining a Oxs_AffineTransformVectorField with a Oxs AffineOrientVectorField to completely rotate a vector field Specify Oxs_BoxAtlas atlas xrange 80e 9 80e 9 yrange 80e 9 80e 9 zrange 0 40e 9 proc Tra p xyz H f if y lt x amp amp y lt 0 5 return list 0 1 0 return list 0 0 0 Specify Oxs_ScriptVectorField trap script Trap atlas atlas Specify Oxs_AffineOrientVectorField orient field trap M 0 1 0 1 00 O 01 offset 20e 9 0 0 inverse 1 Specify Oxs_AffineTransformVectorField rot field orient M 0 1 0 1 00 0O 01 98 proc Threshold vx vy vz set magsq expr vx vxt vy vy vz vz if magsq gt 0 return 8e5 return 0 0 Specify Oxs_ScriptScalarField Ms vector_fields rot script Thre
146. e SetOptions Sec 17 2 2 documentation for details Oxs MinDriver provides 9 scalar outputs and 2 vector field outputs The scalar outputs are e Stage current stage number counting from 0 e Stage iteration number of successful evolver steps in the current stage e Iteration number of successful evolver steps in the current simulation 81 e Mx mx magnetization component in the x direction averaged across the entire simulation in A m Mx or normalized units mx depending on the setting of the normalize_aveM_output option e My my magnetization component in the y direction averaged across the entire simulation in A m My or normalized units my depending on the setting of the normalize_aveM_output option e Mz mz magnetization component in the z direction averaged across the entire simulation in A m Mz or normalized units mz depending on the setting of the normalize_aveM_output option e Max Spin Ang maximum angle between neighboring spins having non zero magnetization M measured in degrees The definition of neighbor depends on the mesh but for Oxs_RectangularMesh the neighborhood of a point consists of 6 points those nearest forward and backward along each of the 3 coordinate axis directions e Stage Max Spin Ang the largest value of Max Spin Ang obtained across the current stage in degrees e Run Max Spin Ang the largest value of Max Spin Ang obtained across the current run in d
147. e with one spin rotating faster than or at least as fast as all the others If the start point was not the result of a successful line minimization from the previous stage then the first bracket attempt 74 step is sized so that the fastest moving spin rotates through the angle specified by minimum bracket _step In the more usual case that the start point is a minimum from the previous line minimization stage the initial bracket attempt step size is set to the distance between the current start point and the start point of the previous line minimization stage The energy and gradient of the energy are examined at the candidate bracket point to test if an energy minimum lies in the interval If not the interval is extended based on the size of the first bracket attempt interval and the derivatives of the energy at the interval endpoints This process is continued until either a minimum is bracketed or the fastest moving spin rotates through the angle specified by maximum_bracket_ step If the bracketing process is successful then a one dimensional minimization is carried out in the interval using both energy and energy derivative information Each step in this process reduces the width of the bracketing interval This process is continued until either the angle between the line direction and the computed energy gradient is within line_minimum_angle_precision degrees of orthogonal or the width of the interval relative to the distance of the
148. e TAB key may be used to change the active subwindow The SHIFT TAB key combination also changes the active subwindow in reverse order When the active subwindow is the display window the following key combinations are active e CTRL o same as menu selection File Open e CTRL s same as menu selection File Save as e CTRL p same as menu selection File Print e CTRL c same as menu selection Options Configure e CTRL v launches viewpoint selection menu View Viewpoint e CTRL w same as menu selection View Wrap Display e CTRL f same as menu selection View Fill Display e HOME First fill then wrap the display e CTRL space same as menu selection View Center Display e CTRL r same as menu selection View Rotate ccw e SHIFT CTRL r same as menu selection View Rotate cw e INSERT decrease arrow subsample by 1 e DEL increase arrow subsample by 1 140 SHIFT INSERT decrease arrow subsample by factor of 2 e SHIFT DEL increase arrow subsample by factor of 2 PAGEUP increase the zoom value by a factor of 1 149 e PAGEDOWN decrease the zoom value by a factor of 1 149 SHIFT PAGEUP increase the zoom value by factor of 2 SHIFT PAGEDOWN decrease the zoom value by factor of 2 e ESC revert to previous data scale and zoom values When the active subwindow is the control bar s coordinate axes display the following key combinations are active
149. e and app mmpe in the OOMMF distribution Refer to the mif_path variable in batchsolve tcl for the complete list If interface is set to 1 enabled batchsolve registers with the account service direc tory application and mmLaunch will be able to provide an interactive interface Using this interface batchsolve may be controlled in a manner similar to mmSolve2D Sec 10 1 The interface allows you to pause un pause and terminate the current simulation as well as to attach data display applications to monitor the solver s progress If more interactive control is needed mmSolve2D should be used If interface is 0 disabled batchsolve does not register leaving it without an in terface unless it is sourced into another script e g batchslave tcl that arranges for an interface on the behalf of batchsolve Use the start_paused switch to monitor the progress of batchsolve from the very start of a simulation With this switch the solver will be paused immediately after loading the specified MIF file so you can bring up the interactive interface and connect display ap plications before the simulation begins Start the simulation by selecting the Run command from the interactive interface This option cannot be used if interface is disabled The end_paused switch insures that the solver does not automatically terminate after completing the specified simulation This is not generally useful but may find application when batchsolve is cal
150. e indicated direction The Shift key used in combination with an arrow keys double the pan step size while the Control key halves it The menu selection File Reset reinitializes the mmGraph application to its original state releasing all data and clearing the axis menus The menu selection File Exit terminates the application The menu Help provides the usual help facilities Details The axes menus are configured based on incoming data As a result these menus are initially empty If a graph widget is scheduled to receive data only upon control point or stage done events in the solver it may be a long time after starting a problem in the solver before the graph widget can be configured Because mmGraph keeps all data up to the limit imposed by the Point buffer size data loss is usually not a problem Of more importance is the fact that automatic data saving can not be set up until the first data point is received As a workaround the solver initial state may be sent interactively as a dummy point to initialize the graph widget axes menus Select the desired quantities off the axes menus and use the Options clear Data command to remove the dummy point from mmGraph s memory The File Save As dialog box may then be used with the Auto Save option enabled to write out an empty table with proper column header information Subsequent data will be written to this file as they arrive 133 13 Vector Field Display mmDisp File View
151. e initial magnetization configuration The RGlob command is not available if the MIFinterp safety option is set to safe in the options tcl customization file Sec 2 3 2 If MIFinterp safety is set to unsafe then the standard and more capable Tcl glob command will be available Schedule The Schedule command is used to setup outputs from the MIF file This func tionality is critical for solvers running in batch mode but is also useful for setting up default connections in interactive mode The syntax for the Schedule command is Schedule lt outname gt lt desttag gt lt event gt lt frequency gt The Schedule command mirrors the interactive output scheduling provided by the Oxsii and Boxsi graphical interfaces Sec 7 The first parameter to the Schedule command is the name of the output being scheduled These names are the same as those appearing in the Outputs list in the Oxs graphical interfaces for example DataTable or Oxs_CubicAnisotropy Nickel Field The name must be presented to the Schedule command as a single argument if the name includes one or more spaces then use double quotes to protect the spaces Aside from the DataTable output which is always present the outname s are MIF file dependent The second parameter to the Schedule command is a destination tag This is a tag associated to a running application by a previous Destination command see above The symbolic destination tag replaces the applicati
152. e normalized i e unit magnetization m is the value specified by start dm The units are degrees with default value 0 01 The four remaining entries error_rate absolute_step_error relative _step_error and step_headroom control fine points of stepsize selection and are intended for advance use only Given normalized magnetization m t at time t and position 7 and candidate magnetization m t At at time t At the error at position 7 is estimated to be Error m t At m t At 2 where the derivative with respect to time m is computed using the Landau Lifshitz ODE 2 First order methods essentially assume that m is constant on the interval t t At the above formula uses the difference in m at the endpoints of the interval to estimate guess how untrue that assumption is A candidate step is accepted if the maximum error across all positions 7 is smaller than absolute_step_error error_rate x At and relative_step_error xX Mmax At where Mypax is the maximum value of m across all i at time t If the step is rejected then a smaller stepsize is computed that appears to pass the above tests and a new candidate step is proposed using that smaller stepsize times step_headroon Alternatively if the step is accepted then the error information is used to determine the stepsize for the next step modified in the same manner by step_headroon The error calculated above is in terms of unit magnetizations so the nat
153. e pointwise effective field A m 111 7 is the Landau Lifshitz gyromagnetic ratio m A s a is the damping coefficient dimensionless Compare to 2 page 66 The effective field is defined as E Heg Ho aM The average energy density E is a function of M specified by Brown s equations 4 includ ing anisotropy exchange self magnetostatic demagnetization and applied field Zeeman terms The micromagnetic problem is impressed upon a regular 2D grid of squares with 3D magnetization spins positioned at the centers of the cells Note that the constraint that the grid be composed of square elements takes priority over the requested size of the grid The actual size of the grid used in the computation will be the nearest integral multiple of the grid s cell size to the requested size It is important when comparing the results from grids with different cell sizes to account for the possible change in size of the overall grid The anisotropy and applied field energy terms are calculated assuming constant magne tization in each cell The exchange energy is calculated using the eight neighbor bilinear interpolation described in 5 with Neumann boundary conditions The more common four neighbor scheme is available as a compile time option Details can be found in the source code file oommf app mmsolve magelt cc The self magnetostatic field is calculated as the convolution of the magnetization against a kernel that
154. e processed in the order in which they appear in the the MIF file No desttag may appear in more than one Destination command and no two destination tags may refer to the same application instance To insure the latter 182 the user is advised to place all Destination commands referring to specific instances e g mmDisp Spock before any Destination commands using generic application references e g mmDisp Otherwise a generic reference might be associated to a running application holding a nickname that is referenced by a later Destination command The tag association by the Destination command is only known to the solver reading the MIF file In contrast assigned instance nicknames are recognized across applica tions In particular multiple solvers may reference the same running application by nickname For example several sequential solver runs could send stage output to the same mmGraph widget to build up overlapping hysteresis loops The last parameter to the Destination command is the optional new keyword If present then a fresh copy of the requested application is always launched for as sociation with the given tag The new option can be safely used with any generic application reference but caution must be taken when using this option with specific instance references because an error is raised if the requested nickname is already in use Ignore The Ignore command takes an arbitrary number of arguments which are thrown a
155. e should define a 3x3 linear transform and its time deriva tive The transform must be differentiable with respect to time throughout each stage but is allowed to be discontinuous between stages As noted in the Oxs ScriptUZeeman documentation it is important that the derivative informa tion be correct The transform is applied pointwise to the fixed field obtained from vector_field_spec which is additionally scaled by multiplier The multiplier entry is optional with default value 1 0 The type transform_type value declares the format of the result returned from the Tcl script Recognized formats are identity diagonal symmetric and general The most flexible is general which indicates that the return from the Tcl script is a list of 18 numbers defining a general 3x3 matrix and its 3x3 matrix of time derivatives The matrices are specified in row major order i e Mii Mi2 Mi3 Mp1 M22 Of course this is a long list to construct if the desired transform is symmetric or diagonal then the type may be set accordingly to reduce the size of the Tcl result string Scripts of the symmetric type return 12 numbers the 6 upper diagonal entries in row major order i e Mii M12 Mi3 M22 Mo3 M33 for both the transformation matrix and its time derivative Use the diagonal type for diagonal matrices in which case the Tcl script result should be a list of 6 numbers The simplest transform_type is identity which is the default This identifi
156. e total energy in joules contributed by this energy term and the vector field output Field which is the pointwise field in A m If the code was compiled with the macro NDEBUG not defined then there will be an additional scalar output Calc count which counts the number of times the term has been calculated in the current simulation This is intended for debugging purposes only this number should agree with the Energy calc count value provided by the evolver e Anisotropy Energy Oxs_UniaxialAnisotropy Uniaxial magneto crystalline anisotropy Specify block takes 2 parameters the anisotropy direction axis and either the crystalline anisotropy constant K1 in J m or the anistropy field Ha in A m The axis direction is an easy axis if K1 or Ha is gt 0 or is the normal to the easy plane if K1 or Ha is lt 0 Both axis and K1 Ha may be varied cellwise across the mesh The anisotropy axis direction is initialized with a vector field object while K1 or Ha is initialized with a scalar field object The axis direction must be non zero at each point and will be normalized to unit magnitude before being used The energy computed by this term is non negative in all cases Examples diskarray mif stdprob3 mif grill mif Oxs_CubicAnisotropy Cubic magneto crystalline anisotropy Specify block takes 3 parameters crystalline anisotropy either as anisotropy constant K1 in J m or anisotropy field Ha in A m and anisotropy
157. eader block the new valueunits record replaces the valueunit record of OVF 1 0 Instead of a single unit value valueunits should be a Tcl list of value units each treated as an unparsed label The list should either have length N as specified by valuedim in which case each element denotes the units for the corresponding dimension index or else the list should have length one in which case the single element is applied to all dimension indexes The old valueunit record is not allowed in OVF 2 0 files 4 In the Segment Header block the new valuelabel1s record is required This should be an N item Tcl list of value labels one for each value dimension The labels identify the quantity in each dimension For example in an energy density file N would be 1 valueunits could be J m and valuelabels might be Exchange energy density 5 Inthe Segment Header block the records valuemultiplier boundary ValueRangeMaxMag and ValueRangeMinMag of the OVF 1 0 format are not supported 225 6 In the Data block for regular meshes each record consists of N values where N is the value dimension as specified by the valuedim record in the Segment Header The node ordering is the same as for the OVF 1 0 format For irregular meshes each record consists of N 3 values where the first three values are the x y and z components of the node position For data blocks using text representation with N 3 the Data block in OVF 1 0 and OVF 2 0 files
158. ed by the average option A couple of examples are valfunc Ms A m vmag valfunc M110 A m vxt vy sqrt 2 As with the valexpr string for index the fenexpr string should be surrounding by single quotes on Unix in order to forestall interpolation of the special variables by the shell On Windows the fcnexpr string should be surrounded by double quotes as usual to protect embedded spaces The output value is not affected by the normalize option Multiple instances of the valfunc option on the command line will result in 157 multiple columns in the output file in the order specified These additional columns will be append to the right of all other columns in the output file infile Input file list Files must be one of the recognized formats OVF 1 0 or VIO in a rectangular mesh subformat The file specification options require some explanation Input files may be specified either by an explicit list infile or by giving a wildcard pattern e g ipat omf which is expanded in the usual way by avf2odt using the Tcl command glob Unix shells sh csh etc automatically expand wildcards before handing control over to the invoked application so the ipat option is not usually needed although it is useful in case of a command line too long error DOS does not do this expansion so you must use ipat to get wildcard expansion in Windows The resulting file list is sorted based on the filesort specific
159. eeman energy density Anisotropy field End Header Each data records consists of N 3 values the x y z node location followed by the N value components In this example N 3 5 the two value components are in units of J m 3 and A m corresponding to Zeeman energy density and a magneto crystalline anisotropy field respectively Begin data text 0 5 0 5 0 5 500 4e4 9 5 0 50 5 300 5e3 0 5 4 5 0 5 400 4e4 9 54 5 0 5 200 5e3 5 0 2 50 5 350 2 1e4 End data text End segment Figure 12 Commented OVF 2 0 sample file 19 3 The OVF 0 0 format The OVF 0 0 format is a simple ASCII text format supporting irregularly sampled data It is intended as an aid for importing data from non OOMMF programs and is backwards compatible with the format used for problem submissions for the first wMAG standard problem Users of early releases of OOMMF may recognize the OVF 0 0 format by its previous name the Simple Vector Field SVF format It came to the attention of the OOMMF developers that the file extension svf was already registered in several MIME systems to indicate the Simple Vector Format a vector graphics format To avoid conflict we have stopped using the name Simple Vector Field format although OOMMEF software still 16http www ctcms nist gov 7Erdm stdprob_1 html http www softsource com svf 227 recognizes the svf extension and you may still find example files and othe
160. efault Ellipse The sample or the magnetically active portion thereof is an ellipse inscribed into the rectangular area specified by Part Width and Part Height Ellipsoid Similar to the Ellipse shape but the part thickness is varied to simulate an ellip soid with axis lengths of Part Width Part Height and Part Thickness Oval r Shape is a rounded rectangle where each corner is replaced by a quarter circle with radius r where 0 lt r lt 1 is relative to the half width of the rectangle Pyramid overhang Shape is a truncated pyramid with ramp transition base width overhang spec ified in meters Mask filename Shape and thickness are determined by a bitmap file the name of which is specified as the second parameter The overall size of the simulation is still determined by Part Width and Part Height above the bitmap is spatially scaled to fit those dimensions Note that this scaling will not be square if the aspect ratio of the part is different from the aspect ratio of the bitmap The given filename must be accessible to the solver application At present the bitmap file must be in either the PPM portable pixmap GIF or BMP formats Formats other than the PPM P3 text format may be handled by spawning an any2ppm Sec 16 1 subprocess White areas of the bitmap are interpreted as being non magnetic or having 0 thickness all other areas are assumed to be composed of the material specified 212
161. egionA reported by the Oxs_MultiAtlas will be the same as regionA reported by atlasA but regionB as reported by the Oxs_MultiAtlas will be the L shaped volume of those points in atlasB s regionB not inside regionA If the Oxs_MultiAtlas is constructed with atlasB first and atlasA second then regionB as reported by the Oxs_MultiAtlas would agree with that reported by atlasB but regionA would be empty NOTE The attributes key label cf Sec 17 1 3 5 is not supported by this class Examples manyregions multiatlas mif spinvalve mif spinvalve af mif yoyo mif Oxs_ScriptAtlas An atlas where the regions are defined via a Tcl script The specify block has the form Specify Oxs_ScriptAtlas name xrange rmin xmax yrange ymin ymax zrange zmin zmar regions rname_1 rname_2 rname_n script_args args_request script Tcl_script 50 Here xmin xmaz are coordinates in meters specifying the extents of the axes parallel rectangular parallelepiped enclosing the total volume being identified This volume is subdivided into n sub regions using the names as given in the regions list The script is used to assign points to the various regions Appended to the script are the arguments requested by script_args in the manner explained in the User Defined Support Procedures section Sec 17 1 3 6 of the MIF 2 file format documentation The value args_request should be a subset of relpt rawpt minpt maxpt span If scrip
162. egrees As is the case for the Oxs_TimeDriver the three Max Spin Ang outputs are disabled by default They can be enabled by setting the report_max_spin_angle option to to 1 The vector field outputs are e Magnetization magnetization vector M in A m e Spin unit magnetization m This output ignores the vector_field_output_format precision setting instead always exporting at full precision Examples cgtest mif stdprob3 mif 7 3 6 Field Objects Field objects return values either scalar or vector as a function of position These are frequently used as embedded objects inside Specify blocks of other Oxs_Ext objects to ini tialize spatially varying quantities such as material parameters or initial magnetization spin configurations Units on the returned values will be dependent upon the context in which they are used Scalar field objects are documented first Vector field objects are considered farther below Oxs_UniformScalarField Returns the same constant value regardless of the import po sition The Specify block takes one parameter value which is the returned constant 82 value This class is frequently embedded inline to specify homogeneous material pa rameters For example inside a driver Specify block we may have Specify Oxs_TimeDriver Ms Oxs_UniformScalarField value 8e5 As discussed in the MIF 2 documentation Sec 17 1 3 2 page 188 when embedding Oxs_UniformScalarField or Oxs_U
163. elax Step and Pause place the solver into one of four run states In the Pause state the solver sits idle awaiting further instructions If Step is selected then the solver will move forward one iteration and then Pause In Relax mode the solver takes at least one step and then runs until it reaches a stage boundary at which point the solver is paused In Run mode the solver runs until the end of the problem is reached Interactive output is available in all modes the scheduled outputs occur appropriately as the step and stage counts advance Directly below the progress control buttons are two display lines showing the name of the input MIF file and the current run state Below the run state Status line is the stage display and control bar The simulation stage may be changed at any time by dragging the scroll bar or by typing the desired stage number into the text display box to the left of the scroll bar Valid stage numbers are integers from 0 to N 1 where N is the number of stages specified by the MIF input file 38 Details The simulation model construction is governed by the Specify blocks in the input MIF file Therefore all aspects of the simulation are determined by the specified Oxs_Ext classes Sec 7 3 Refer to the appropriate Oxs_Ext class documentation for simulation and com putational details Known Bugs A bug in the network traffic handling code of Tcl on Windows 9X systems can sometimes interfere with communica
164. eld_spec scalarvalue fieldvalue scalarside sign surface2 atlas atlas_spec region region_label scalarfield scalarfield_spec scalarvalue fieldvalue scalarside sign Here sigma and sigma2 are the bilinear and biquadratic surface interfacial exchange energies in J m Either is optional with default value 0 The surfacel and surface2 sub blocks describe the two interacting surfaces Each description consists of 5 name values pairs which must be listed in the order shown In each sub block atlas_spec specifies an atlas and region_label specifies a region in that atlas These bound the extent of the desired surface The following scalarfield scalarvalue and scalarside entries define a discretized surface inside the bounding region Here scalarfield_spec references a scalar field object fieldvalue should be a floating point value and sign should be a single character either or If sign is then any point for which the scalar field object takes a value less than or equal to the scalarvalue value is considered to be inside the surface Conversely if sign is then any point for which the scalar field object has value greater than or equal to the scalarvalue value is considered to be inside the surface The discretized surface determined is the set of all points on the problem mesh that are in the bounding region are either on the surface or lie on the inside side of the surface an
165. ely setting either too fine will produce additional line minimization steps that do noth ing to improve convergence towards the energy minimum in the full 3N dimensional magnetization space The energy precision parameter estimates the relative precision of the energy com putations This is used to introduce a slack factor into the energy comparisons during the bracketing and line minimization stages that is if the computed energy values at two points have relative error difference smaller than eprecision they are treated as having the same energy The default value for eprecision is le 10 The true precision will depend primarily on the number of spins in the simulation It may be necessary for very large simulations to increase the eprecision value The method parameter can be set to either Fletcher Reeves or Polak Ribiere to specify the conjugate gradient direction selection algorithm The default is Fletcher Reeves which has somewhat smaller memory requirements The last parameter fixed_spins performs the same function as for the Oxs_EulerEvolve class The Oxs_CGEvolve module provides seven scalar outputs and two vector field outputs The scalar outputs are e Max mxHxm maximum m x H x mJ in A m m is the unit magnetization direction e Total energy in joules e Delta E change in energy between last step and current step in joules e Energy calc count number of times total energy has been calculated e Bracket count total
166. ename hanisotropy ohf basename hzeeman ohf etc where basename is the input omf magnetization file name stripped of any trailing omf or ovf extension 16 11 MIF Format Conversion mifconvert The mifconvert utility converts any of the MIF Sec 17 page 179 formats into the MIF 2 1 format used by the Oxs 3D solvers Sec 7 It can also convert between the MIF 1 1 and MIF 1 2 formats generated by micromagnetic problem editor mmProbEd Sec 8 As a migration aid mifconvert will convert most files from the obsolete MIF 2 0 format used by OOMMF 1 2a2 into the newer MIF 2 1 format 172 Launching The mifconvert launch command is tclsh oommf tcl mifconvert f force format fmt h help nostagecheck q quiet unsafe v version input_file output_file where f or force Force overwrite of output file Optional format fmt Specify output format where fmt is one of 1 1 1 2 or 2 1 The 1 1 and 1 2 formats are available only if the input file is also in the 1 x format Conversion from the 2 1 format to the 1 x formats is not supported Optional default setting is 2 1 h or help Print help information and stop nostagecheck Sets the stage_count_check parameter in the output Oxs_Driver Specify block Sec 7 3 5 page 77 to 0 this disables stage count consistency checks inside the Oxs solver Optional This option is only active when the output MIF format is 2 1 q or quiet Suppress normal i
167. enient graphical interface for launching applica tions The main uses for the bootstrap application are launching mmLaunch launching pimake launching programs which make up the OOMMF Batch System Sec 10 2 and other programs that are inherently command line driven and in circumstances where the user wishes to precisely control the command line arguments passed to an OOMMF application or the environment in which an OOMMF application runs Platform Issues On most Unix platforms if oommf tcl is marked executable it may be run directly i e without specifying tclsh This works because the first few lines of the oommf tc1 Tcl script are bin sh exec tclsh 0 1 When run the first tclsh on the execution path is invoked to interpret the oommf tc1 script If the Tcl shell program cannot be invoked by the name tclsh on your computer edit the first lines of oommf tcl to use the correct name Better still use symbolic links or some other means to make the Tcl shell program available by the name tclsh The latter solution will not be undone by file overwrites from OOMMEF upgrades If in addition the directory path to oommf is in the execution path the command line can be as simple as oommf tcl appName from any working directory On Windows platforms because oommf tcl has the file extension tcl it is normally associated by Windows with the wish interpreter The oommf tcl script has been specially written so th
168. entVectorField class page 97 for analogous operations on vector fields Example sample rotate mif Oxs_AffineTransformScalarField Like the Oxs_AffineOrientScalarField class this class composes an affine transform with a separate scalar field but in this case the affine transform is applied after the field evaluation The Specify block has the form Specify Oxs_AffineTransformScalarField name 90 field scalar_field_spec multiplier mult offset off inverse invert_flag If F x represents the scalar field specified by the field value then the resulting scalar field is mult x F x off Since the output from F is a scalar both multiplier and offset are scalars If inverse is 1 then the transform is changed to F x off mult provided mult is non zero The default values for mult off and invert_flag are 1 0 and 0 respectively The field value is the only required entry The functionality provided by Oxs_AffineTransformScalarField can also be pro duced by the Oxs_ScriptScalarField class page 85 with the scalar fields entry but the Oxs_AffineTransformScalarField class is faster and has a simpler interface See also the Oxs_AffineTransformVectorField class page 97 for analogous opera tions on vector fields Example sample rotate mif Oxs_ImageScalarField This class creates a scalar field using an image The Specify block has the form Specify Oxs_ImageScalarField name image pic invert invert_flag m
169. eprecated Use Default Control Point Spec instead Randomizer Seed Value with which to seed random number generator Optional Default value is 0 which uses the system clock to generate a semi random seed Max Time Step Limit the maximum ODE step size to no larger than this amount in seconds Optional Min Time Step Limit the minimum ODE step size to no less than this amount in seconds Optional User Comment Free form comment string that may be used for problem identifica tion Optional MIF 1 1 Example from the OOMMF User s Guide All units are SI HHHHHHHHHHHHHHHHH MATERIAL PARAMETERS HHHHHHHHHHHHHHHHHHH Ms 800e3 Saturation magnetization in A m A 13e 12 Exchange stiffness in J m K1 0 5e3 Anisotropy constant in J m 3 Anisotropy Type uniaxial One of lt uniaxial cubic gt Anisotropy Dir1 1 0 0 Directional cosines wrt to 216 coordinate axes HHHHHHHHHHHHHHHHH DEMAG SPECIFICATION HHHHHHHHHHHHHHHHH Demag Type ConstMag One of lt ConstMag 3dSlab 2dSlab 3dCharge FastPipe None gt HHHHHHHHHHHHHHHHHHHHE PART GEOMETRY HHHHHHHHHHHHHHHHH HEHEHE Part Width 0 25e 6 Nominal part width in m Part Height 1 0e 6 Nominal part height in m Part Thickness 1e 9 Part thickness in m Cell Size 7 8125e 9 Cell size in m Part Shape One of lt Rectangle Ellipse Oval Mask gt Optional HHHHHHHHHHHHHHHH INITIAL MAGNETIZATION HHHHHHHHHHHHHHHEH Init Mag Un
170. epresented as a sublist with a repeat count of 4 like so 1 1 1 2 4 1 3 expand Here the expand keyword when appearing as the last element of the top level list enables the group expansion mechanism Any preceding element such as 1 2 4 that 1 is a proper sublist and 2 has a positive integer as the last element is treated as a grouped sublist with repeat count given by the last element No element of the top level list is ever interpreted as a repeat count For example the short form of the list 1e 9 1e 9 1e 9 1e 9 1e 9 1e 9 1e 9 6 expand Note the additional level of brace grouping Grouped lists may also be nested as in this example 5 0 4 5 14 5 23 5 3 2 expand which is equivalent to 5 0 51 5 2 5 2 5 2 5 3 5T 5 2 5 2 5 2 5 3 190 There are some difficulties with this mechanism when the list components are strings such as filenames that may contain embedded spaces For example consider the list file 3 file 3 5 file If we tried to write this as file 3 2 5 file expand we would find that because of the nested grouping rules this grouped list gets expanded into file file file file file file 5 file Here the trailing 3 in file 3 is interpreted as a repeat count Following normal Tcl rules the double quotes are treated as equivalents to braces for grouping purposes However the keyword noexpand may be used to disable further expansion l
171. er generator This random number generator is specified by the OMF_RANDOM macro in the ocport h file found in the system specific subdirectory of oommf pkg oc The standard Tcl expr rand command is also available RandomSeed Initializes both the Tcl and the C library random number generators If no parameter is given then a seed is drawn from the system clock Otherwise one integer parameter may be specified to be used as the seed Report Intended primarily as a MIF debugging aid Report takes one string argument that is printed to the solver interface console and the Oxs log file It is essentially a replacement for the standard Tcl puts command which is not available in safe interpreters ReadFile The Tcl read command is absent from safe interpreters The ReadFile com mand is introduced as a replacement available in custom and unsafe interpreters ReadFile takes two arguments the file to be read and an optional translation specifi cation The file may either be specified with an absolute path i e one including all its directory components or with a relative path interpreted with respect to the directory containing the MIF file The OOMMFRootDir command can be used to advantage to locate files in other parts of the OOMMF directory tree The translation specification should be one of binary auto the default image or floatimage The first two translation modes provide the functionality of the translation option of the Tc
172. er of spins in the simu lation Once a minimum has been found along a line a new direction is chosen that is ideally orthogonal to all preceding directions but related to the gradient of the en ergy taken with respect to the magnetization In practice the line direction sequence cannot be extended indefinitely the parameters gradient_reset_angle and gradi ent_reset_count control the gradient resetting process The first checks the angle between the new direction and the gradient If that angle is larger than reset_angle expressed in degrees then the selected direction is thrown away and the conjugate gradient process is re initialized with the gradient direction as the new first direction In a similar vein count specifies the maximum number of line directions selected before resetting the process Because the first line in the sequence is selected along the gradi ent direction setting count to 1 effectively turns the algorithm into a steepest descent minimization method The default values for reset_angle and count are 80 degrees and 50 respectively Once a minimization direction has been selected the first stage of the line minimization is to bracket the minimum energy on that line i e given a start point on the line the location of the minimum from the previous line minimization find another point on the line such that the energy minimum lies between those two points As one moves along the line the spins in the simulation rotat
173. er to override default settings To change the graph title simply enter the desired title into the Title field To set the axis labels deselect the Auto Label option in this dialog box and fill in the X Label Y1 Label and Y2 Label fields as desired The axis limits can be set in a similar fashion In addition if an axis limit is left empty a default value based on all selected data will be used Select the Auto Scale option to have the axis ranges automatically adjust to track incoming data Use the Auto Offset Y1 and Auto Offset Y2 to automatically translate each curve plotted against the specified axis up or down so that the first point on the curve has a y value of zero This feature is especially useful for comparing variations between different energy curves because for these curves one is typically interested in changes is values rather than the absolute energy value itself The size of the margin surrounding the plot region is computed automatically Larger margins may be specified by filling in the appropriate fields in the Margin Requests section Units are pixels Requested values smaller than the computed default values are ignored The initial curve width is determined by the Ow_GraphWin default_curve_width set ting in the config options tcl and config local options tcl files following the usual method of local customization Sec 2 3 2 The current curve width can be changed by spec ifying the desired width in the Curve Width en
174. erated filename is used for the output filename If f is not specified then a check is made to see if the generated filename already exists If so then an additional 000 or 001 suffix is appended to create an unused filename If the input is coming from stdin i e there is no input filename then the default output is to stdout format fmt Output file format The default is PPM which is the Portable Pixmap P3 text format Setting fmt to BMP will produce files in the uncompressed Windows BMP 24 bits per pixel format If the Tcl Tk Img package is installed then additional formats such as PNG JPEG and TIFF will be available The default output file extension depends on the format selected e g ppm for PPM files and bmp for BMP files noinfo Suppress writing of progress information to stderr o outfile Write output to outfile use to pipe output to stdout Note that if outfile is specified then all output will go to this one file in this case it is unlikely that one wants to specify more than one input file 14http purl oclc org net nijtmans img html 153 infile List of input files to process If none or if an infile is the empty string then read from stdin Note If the output is to stdout and the selected output format is anything other than PPM then the output is first written to a temporary file before being copied to stdout Under normal operation the temporary file will be automat
175. ere as the label portion of a label value pair and the MIF extension command Ignore used outside Specify blocks In particular Ignore takes an arbitrary number of arguments but the value element associated with a comment label must be grouped as a single element just as any other value element 191 17 1 3 5 Attributes Sometimes it is convenient to define label value pairs outside a particular Specify block and then import them using the attributes label For example Specify Oxs_LabelValue probdata alpha 0 5 start_dm 0 01 Specify Oxs_EulerEvolve attributes probdata The Oxs_LabelValue object is an Oxs_Ext class that does nothing except hold label value pairs The attributes label acts as an include statement causing the label value pairs contained in the specified Oxs_LabelValue object to be embedded into the enclosing Specify initialization string This technique is most useful if the label value pairs in the Oxs_LabelValue object are used in multiple Specify blocks either inside the same MIF file or across several MIF files into which the Oxs_LabelValue block is imported using the ReadFile MIF extension command 17 1 3 6 User defined support procedures A number of Oxs_Ext classes utilize user defined Tcl procedures procs to provide extended runtime functionality The most common examples are the various field initialization script classes which call a user specified Tcl proc for each point
176. ereby eliminat ing all disk access at the MIF script level At the other extreme choosing unsafe provides an unrestricted Tcl interpreter This option should be used with caution especially if you are reading MIF files from an unknown or untrusted source After the first line there is considerable flexibility in the layout of the file Generally near the top of the file one places any OOMMFRootDir Parameter and RandomSeed statements as desired This is followed by the major content of the file the various Specify blocks which initialize Oxs_Ext objects Sec 7 3 page 45 179 Atlas one or more e Mesh one Energy terms one or more e Evolver one e Driver one The Specify blocks are processed in order so any block that is referred to by another block must occur earlier in the file For that reason the main atlas object which is referenced in many other Specify blocks is generally listed first The atlas object defines the spatial extent of the simulation and optionally declares subregions inside the simulation volume The mesh object details the spatial discretization of the simulation volume Conven tionally its Specify block follows the Specify block for the main atlas object the mesh is referenced by the driver so in any event the mesh Specify block needs to precede the driver Specify block The energy terms describe the typical micromagnetic energies and fields that deter mine the evolution of the simulation su
177. erface window The Options menu holds two entries Clear Schedule and Restart Flag The first clears all Step and Stage selections from the active output schedules exactly as if the user clicked through the interactive schedule interface one output and destination at a time and disabled each schedule enabling checkbutton This control can be used after loading a problem to override the effect of any Schedule commands in the MIF file The restart flag controls problem load behavior In normal usage the restart flag is not set and the selected problem loads and runs from the beginning Conversely if the restart flag is set then when a problem is loaded a check is made for a restart checkpoint file If the checkpoint file is not found then an error is raised Otherwise the information in the checkpoint file is used to resume the problem from the state saved in that file The restart flag can be set from the Options menu the File Load dialog box or from the command line See the Oxs_Driver documentation Sec 7 3 5 page 77 for information on checkpoint files The Help menu provides the usual help facilities The row of buttons immediately below the menu bar provides simulation progress control These buttons become active once a problem has been loaded The first button Reload re reads the most recent problem MIF input file re initializes the solver and pauses Reset is similar except the file is not re read The remaining four buttons Run R
178. error couldn t open socket no buffer space available OOMMEF uses network sockets for communications between its various components On Windows 9X the socket resources are limited and most OOMMF applications use several sockets The only workaround is to close unneeded OOMMF applications and any other applications that may be using network resources The system command line utility netstat can be used to monitor network communications This problem does not arise on Windows NT or Unix systems In the Cygwin environment on Windows there is an warning like Tcl version mismatch C Cygwin lib tclConfig sh from 8 0p2 Running Tcl 8 0 4 232 12 13 14 This is caused by broken tclConfig sh and tkConfig sh files in the Cygwin distri bution You may ignore the warning or edit the tclConfig sh and tkConfig sh files to change the TCL_PATCH_LEVEL and TK_PATCH_LEVEL values from p2 to 4 How ever the best option is to upgrade Tcl Tk The stock Windows Tcl Tk 8 4 7 and presumably later release works in Cygwin When starting OOMMF in the Cygwin environment on Windows the mmLaunch window appears briefly then disappears without any error messages Some versions of Tcl Tk included with the Cygwin environment i e usr bin tclsh are known to have bugs in the socket code that cause OOMMF to crash in this manner Please build and run OOMMF using a stock Windows Tcl Tk as described in the build instructions for the Cygwin
179. es the transform as the identity matrix which means that effectively no trans form is applied aside from the multiplier option which is still active For the identity transform type script and script_args should not be specified and Oxs_TransformZeeman becomes a clone of the Oxs_FixedZeeman class The following example produces a 1000 A m field that rotates in the ry plane at a frequency of 1 GHz Specify Oxs_TransformZeeman type general script Rotate 1e9 field 0 1000 0 proc Rotate freq stage stagetime totaltime global PI 62 set w expr freq 2 PI set ct expr cos w totaltime set mct expr 1 ct mct is minus cosine w t set st expr sin w totaltime set mst expr 1 st mst is minus sine w t return list ct mst 0 st ct O o 0 1 expr w mst expr w mct 0 expr w ct expr w mst O 0 0 0 This particular effect could be obtained using the Oxs_ScriptUZeeman class be cause the field is uniform But the field was taken uniform only to simplify the example The vector_field_spec may be any Oxs vector field object Sec 7 3 6 For example the base field could be large in the center of the sample and decay towards the edges In that case the above example would generate an applied rotating field that is concentrated in the center of the sample The stage_count parameter informs the Oxs_Driver Sec 7 3 5 as to how many stages the Oxs_Trans
180. es mif varalpha mif Oxs_VecMagScalarField The 0xs_VecMagScalarField class produces a scalar field from a vector field by taking the norm of the vector field on a point by point basis i e lol y0 09 0B The Specify block has the form Specify Oxs_VecMagScalarField name field vector_field_spec multiplier mult offset off The multiplier and offset entries are applied after the vector norm i e the resulting scalar field is mult x v off The default values for mult and off are 1 and 0 respectively The functionality of the Oxs_VecMagScalarField class may be achieved with the Oxs_ScriptScalarField class by using the vector_fields option and a Tcl script to compute the vector norm However this particular functionality is needed frequently enough that a specialized class is useful For example this class can be used in conjunc tion with a vector field object to set both the saturation magnetization distribution M and the initial magnetization Specify Oxs_FileVectorField file1 atlas atlas file filel omf Specify Oxs_TimeDriver basename test evolver evolve stopping _dm_dt 0 01 87 mesh mesh mO filel Ms Oxs_VecMagScalarField field filel t F Example sample vecrotate mif Oxs_ScriptOrientScalarField Scalar fields provide scalar values as a function of position across three space The Oxs_ScriptOrientScalarField class is used to compose a transformation on the input position before
181. es size as the mouse is dragged If the left mouse button is depressed then the x axis and yl axis are rescaled to just match the extents of the displayed rectangle If the right mouse button or alternatively the shift key left mouse button is used then the x axis and y2 axis are rescaled An arrow is drawn against the rectangle indicating which y axis will be rescaled The rescaling may be canceled by positioning the mouse pointer over the initial point before releasing the mouse button The zoom box feature is similar to the mouse zoom 132 control in the mmDisp Sec 13 application except that here there is no un zooming mouse control The PageUp and PageDown keys may also be used to zoom the display in and out Use in conjuction with the Shift key to jump by larger steps or with the Control key for finer control The Options Rescale command or the Options Configure dialog box may also be used to reset the graph extents If mmGraph is being used to display data from a running solver and if Auto Scale is selected in the Options Configure dialog box then the graph extents may be changed automatically when a new data point is received This is inconvenient if one is simultaneously using the zoom feature to examine some portion of the graph In this case one might prefer to disable the Auto Scale feature and manually pan the display using the keyboard arrow keys Each key press will translate the display one half frame in th
182. es the patterns gz z and zip and invokes the translation program gzip dc to perform the translation In this way support for reading compressed files is built in to mmDisp on any platform where the gzip program is installed There are two categories of translations supported decompression and format conversion Both are modified by the usual method of local customization Sec 2 3 2 The command governing decompression in the customization file is of the form Oc_Option Add Nb_InputFilter decompress gz zip gzip dc The final argument in this command is a list with an even number of elements The first element of each pair is the filename extension The second element in each pair is the command line for launching the corresponding translation program To add support for bzip2 compressed files change this line to Oc_Option Add Nb_InputFilter decompress gz zip gzip dc bz2 bunzip2 This option also affects other applications such as mmGraph that support on the fly decompression In all cases the decompression program must accept compressed input on standard input and write the decompressed output to standard output 135 There is also input translation support for filters that convert from foreign i e non OOMMF file formats For example if a program foo were known to translate a file format identified by the extension bar into the OVF file format that program could be made known to mmDisp
183. evaluation by a scalar field The Specify block has the form Specify Oxs ScriptOrientScalarField name field scalar_field_spec script Tcl_script script_args args_request atlas atlas_spec xrange rmin zmar yrange ymin ymaz zrange zmin zmar The field argument should refer to a scalar field object The script is a Tcl script that should return a position vector that will be sent on the field object to ulti mately produce a scalar value The arguments to the Tcl_script are determined by script_args which should be a subset of relpt rawpt minpt maxpt span If any arguments other than rawpt are requested then the bounding box must be specified by either the atlas option or else through the three xrange yrange zrange entries The default value for script_args is relpt The Oxs ScriptOrientScalarField class can be used to change the orientation of a scalar field as in the following simple example which reflects the filetmag scalar field across the yz plane Specify Oxs_FileVectorField file1 atlas atlas file filel omf Specify Oxs_VecMagScalarField fileimag field filel 88 proc Reflect x y z xmin ymin zmin xmax ymax zmax return list expr xmax xmin x y z Specify Oxs_ScriptOrientScalarField reflect field fileimag script Reflect script_args rawpt minpt maxpt atlas atlas See also the Oxs_ScriptOrientVectorField class page 96 for analogous operations on vector
184. f spatial location This is a generalization of the Anisotropy Dirl 2 records The value for this record should be one of lt Constant UniformXY UniformS2 gt Constant uses the values specified for Anisotropy Dirl and Dir2 with no dispersion UniformXY ig nores the values given for Anisotropy Dirl and Dir2 and randomly varies the anisotropy directions uniformly in the xy plane UniformS2 is similar but randomly varies the anisotropy directions uniformly on the unit sphere S This record is optional the default value is Constant Edge K1 Anisotropy constant similar to crystalline anisotropy constant K1 described above but applied only along the edge surface of the part This is a uniaxial anisotropy directed along the normal to the boundary surface Units are J m with positive values making the surface normal an easy axis and negative values making the surface an easy plane The default value for Edge K1 is 0 which disables the term Do Precess If 1 then enable the precession term in the Landau Lifshitz ODE If 0 then do pure damping only Optional default value is 1 Gyratio The Landau Lifshitz gyromagnetic ratio in m A s This is optional with default value of 2 21 x 10 See the discussion of the Landau Lifshitz ODE under the Damp Coef record identifier description 210 e Damp Coef The ODE solver in OOMMF integrates the Landau Lifshitz equation 10 12 written as dM _ Iya oe 5 M x He dg MX Mee ag
185. field set colorimage ReadFile mirror ppm floatimage set imagewidth lindex colorimage 0 set imageheight lindex colorimage 1 set imagedepth lindex colorimage 2 Depth value should be 1 if imagedepth 1 Report ReadFile returned unexpected list value proc ColorField xyzif global colorimage imagewidth imageheight set i expr int floor double x imagewidth if i gt imagewidth set i expr imagewidth 1 set j expr int floor double 1 y imageheight if j gt imageheight set j expr imageheight 1 set index expr 3 j imagewidtht i 3 3 is to skip header set vx expr 2 lindex colorimage index 1 incr index Red set vy expr 2 lindex colorimage index 1 incr index Green set vz expr 2 lindex colorimage index 1 incr index Blue return list vx vy vz Specify Oxs_ScriptVectorField sample atlas atlas norm 1 0 script ColorField If the input image is large then it is best to work with the image list i e the variable colorimage in the preceding example directly as illustrated above The image list as returned by ReadFile is in a packed format if you make modifications to the list values then the memory footprint of the list can grow substantially The ReadFile command is not available if the MIFinterp safety option is set to safe in the options tcl customization file Sec 2 3 2 RGlob This command is modeled on the Tcl g
186. figuration file Fig 4 page 146 See the Tcl documentation for details of the array set command There are several places in the configuration file where colors are specified Colors may be represented using the symbolic names in oommf config colors config in any of the Tk hexadecimal formats e g RRGGBB or as a shade of gray using the format grayD or sreyD where D is a decimal integer from 0 100 inclusive Examples in the latter two formats are FFFFOO for yellow gray0 for black and gray100 or FFFFFF for white Refer to the default configuration file as we discuss each element of the plot_config array arrow status Set to 1 to display arrows 0 to not draw arrows arrow autosample If 1 then ignore the value of arrow subsample and automatically de termine a reasonable subsampling rate for the arrows Set to 0 to turn off this feature arrow subsample If arrow autosample is 0 then subsample the input vectors at this rate when drawing arrows A value of 0 for arrow subsample is interpreted specially to display all data arrow colormap Select the colormap to use when drawing arrows Should be one of the strings specified in the Colormap section of the Options Configure dialog arrow colorcount Number of discretization levels to use from the colormap A value of zero will color all arrows with the first color in the colormap arrow quantity Scalar quantity the arrow color is to represent Supported val
187. file each new data record as it is received by mmGraph The appended fields will be those chosen at the time of the save operation i e subsequent changing of the curves selected for display does not affect the automatic save operation The automatic save operation continues until either a new output file is specified the Options Stop Autosave control is invoked or mmGraph is terminated The File Print dialog is used to produce a Postscript file of the current graph On Unix systems the output may be sent directly to a printer by filling the Print to entry with the appropriate pipe command e g lpr The exact form is system dependent Controls Graphs are constructed by selecting any one item off the X axis menu and any number of items off the Y1 axis and Y2 axis menus The yl axis is marked on the left side of the graph 130 the y2 axis on the right These menus may be detached by selecting the dashed rule at the top of the list Sample results are shown in the figure at the start of this section When mmGraph is first launched all the axis menus are empty They are dynamically built based on the data received by mmGraph By default the graph limits and labels are automatically set based on the data The x axis label is set using the selected item data label and measurement unit if any The y axes labels are the measurement unit of the first corresponding y axis item selected The Options Configure dialog box allows the us
188. filename In unusual circumstances OOMMF may find a Tcl configuration file which doesn t correctly describe your Tcl in stallation In that case use the environment variable OOMMF_TCL_CONFIG to instruct OOMMF to use a different file that you specify and if necessary edit that file to include a correct description of your Tcl installation Next the oommf tcl platform reports similar information about the wish and Tk configuration The environment variables OOMMF_TK_CONFIG and OOMMF_WISH may be used to tell OOMMF where to find the Tk configuration file and the wish program respectively Following the Tk information are some lines reporting thread build and run status Threads are used by OOMMF to implement parallelism in the Oxs oxsii and boxsi 3D solvers on multi processor multi core shared memory machines In order to build or run a parallel version of OOMMF you must have a thread enabled version of Tcl The Tcl thread status is indicated on the first thread status line If Tcl is thread enabled then the default OOMMF build process will create a threaded version of OOMMF You can override this behavior if you wish to build a non parallel version of OOMMF by editing the oommf threads value in the config platforms file for your platform If Tcl and OOMMF threads are enabled then the next line will show the default number of threads run by the Oxs solvers This value may vary between machines depending on the number of processors in
189. fixed and free layers may be instead specified separately through P_fixed P_free Lambda_fixed and Lambda_free Otherwise P_fixed P_free P and Lambda fixed Lambda free Lambda Lambda must be larger than or equal to 1 set Lambda 1 to remove the dependence of on m m If you want non zero it is set directly as eps_prime Current density J and unit polarization direction mp are required The units on J are A m Positive J produces torque that tends to align m towards m Parameters J mp P Lambda and eps_prime may all be varied pointwise but are fixed with respect to time However J can be multiplied by a time varying profile to model current rise times pulses etc Use the J_profile and J_profile_args options to enable this feature The Jprofile_script should be a Tcl script that returns a single scalar Jprofile_script_args should be a subset of stage stage_time total_time to specify arguments appended to Jprofile_script on each time step Default is the entire set in the order as listed The Oxs_SpinXferEvolve module provides the same five scalar outputs and three vector outputs as Oxs_RungeKutta plus the scalar output average J and the vector field outputs Spin torque which is 7 Ge m x m x m and J mp Development note In the case propogate_mp is enabled mp is actually A 0m 0x where x is the flow direction and A is the cell dimension in that direction The Oxs_SpinXferEvolve
190. formZeeman object wants A value of 0 the default indi cates that the object is prepared for any range of stages The stage_count value given here must be compatible with the stage _count setting in the driver Specify block q v Examples sample2 mif tickle mif rotatecenter mif Oxs_StageZeeman The Oxs_StageZeeman class provides spatially varying applied fields that are updated once per stage In its general form the field at each stage is provided by an Oxs vector field object Sec 7 3 6 determined by a user supplied Tcl script There is also a simplified interface that accepts a list of vector field files Sec 19 one per stage that are used to specify the applied field The Specify block takes the form Specify Oxs StageZeeman name script Tcl_script files list_of_files stage_count number_of_stages multiplier multiplier The initialization string should specify either script or files but not both If a script is specified then each time a new stage is started in the simulation a Tcl command is formed by appending to Tcl_script the 0 based integer stage number This command should return a reference to an Oxs_VectorField object as either the instance name of an object defined via a top level Specify block 63 elsewhere in the MIF file or as a two item list consisting of the name of an Oxs_VectorField class and an appropriate initialization string In the latter case the Oxs_VectorField object will be created a
191. four stages in total If the first field in the second range sublist was different from the second field in the first range sublist then a step would have been added between those field values so five stages would have resulted In this example note that 795 77472 0 001 uo Examples sample mif cgtest mif marble mif Oxs_FixedZeeman Non uniform non time varying applied field This can be used to simulate a biasing field The specify block takes one required parameter which defines the field and one optional parameter which specifies a multiplication factor Specify Oxs_FixedZeeman name field vector_field_spec multiplier multiplier The default value for multiplier is 1 Examples spinvalve mif spinvalve af mif yoyo mif Oxs_ScriptUZeeman Spatially uniform applied field potentially varying as a func tion of time and stage determined by a Tcl script The Specify block has the form Specify Oxs_ScriptUZeeman name script_args args_request script Tcl_script multiplier multiplier stage_count number_of_stages Here script indicates the Tcl script to use The script is called once each itera tion Appended to the script are the arguments requested by script_args in the manner explained in the User Defined Support Procedures section Sec 17 1 3 6 of the MIF 2 file format documentation The value args_request should be a subset of stage stage_time total_time If script_args is not specified the default
192. g targets where nick names are as set by the MIF 2 1 Destination command Sec 17 1 2 test Don t kill anything just test that targets are responding timeout secs Maximum time to wait for response from servers in seconds Default is five seconds oid List of one or more oids OOMMF ID s application names nicknames or the keyword all Glob style wildcards may also be used This field is required there are no default kill targets The killoommf command affects processes that listen to OOMMF message traffic These are the same applications that are listed in the Threads list of mmLaunch Sec 6 The command tclsh oommf tcl killoommf all is essentially equivalent to the File Exit A11 OOMMF menu option in mmLaunch except that killoommf does not shut down any mmLaunch processes An OOMMF application that does not respond to killoommf can be killed by using the OOMMF command line program pidinfo Sec 16 13 to determine its PID process identification as used by the operating system and then using the system facilities for terminating processes e g kill on Unix or the Windows Task Manager on Windows 16 9 Launching the OOMMF host server launchhost Under normal circumstances the OOMMF host server also known as the host service direc tory is automatically launched in the background as needed by client applications However it can be useful primarily in batch compute environments to launch t
193. ge from the default You may layer configuration files by specifying multiple user configuration files on the command line These are processed from left to right with the last value set for each entry taking precedence 16 5 Making PostScript from Vector Fields avf2ps The avf2ps utility creates a collection of color Encapsulated PostScript files from a collec tion of vector field files e g omf ovf which can be embedded into larger PostScript documents or printed directly on a PostScript printer Operation of the avf2ps command is modeled after the avf2ppm command Sec 16 4 and the print dialog box in mmDisp Sec 13 Launching The avf2ps launch command is tclsh oommf tcl avf2ps standard options config file f filter program ipat pattern opatexp regexp opatsub sub v level infile where 163 array set plot_config arrow status arrow colormap arrow colorcount arrow quantity arrow colorphase arrow colorinvert arrow autosample arrow subsample arrow size arrow antialias pixel status pixel colormap pixel colorcount pixel opaque pixel quantity pixel colorphase pixel colorinvert pixel autosample pixel subsample pixel size 1 Black Gray White ee OONO e 1 Teal White Red 225 eOoOroOoOOM M e misc background misc drawboundary misc boundarywidth misc boundarycolor misc boundarypos misc matwidth misc matcolor misc margin misc width misc
194. gnored headers for all columns are reported t output_type Specify the output format Here output_type should be one of the strings odt csv or bare The default is odt the ODT file format Sec 18 Selecting csv will yield a Comma Separated Values CSV file which can be read by many spreadsheet programs The bare selection produces space separated numeric output with no ODT header trailer or comment lines The latter two options are intended as aids for transferring data to third party programs in particular such output is not in ODT format and there is no support in OOMMF for translating back from CSV or bare format to ODT format w colwidth Minimum horizontal spacing to provide for each column on output Optional Default value is 15 col Output column selections These may either be integers representing the position of the column in the input data with the first column numbered as 0 or else arbitrary strings used for case insensitive glob style matching against the column headers The columns are output in match order obtained by processing the column selections from left to right If no columns are specified then by default all columns are selected lt infile Odtcols reads its input from stdin Use the redirection operator lt to read input from a file gt outfile Odtcols writes its output to stdout Use the redirection operator gt to send the output to a file Commonly the s switch is used in
195. gonal alignment The following example produces an antiferromagnetic exchange coupling between the lower surface of the top layer and the upper surface of the bottom layer across a middle spacer layer The simple Oxs_LinearScalarField object is used here to provide level surfaces that are planes orthogonal to the z axis In practice this example might represent a spinvalve where the top and bottom layers would be composed of ferromagnetic material and the middle layer could be a copper spacer Specify Oxs_MultiAtlas atlas atlas Oxs_BoxAtlas name top xrange 0 500e 9 yrange 0 250e 9 zrange 6e 9 9e 9 Foy atlas Oxs_BoxAtlas name spacer xrange 0 500e 9 yrange 0 250e 9 zrange 3e 9 6e 9 atlas Oxs_BoxAtlas name bottom xrange 0 500e 9 yrange 0 250e 9 57 zrange 0 3e 9 Specify Oxs_LinearScalarField zheight vector 0 0 1 norm 1 0 Specify Oxs_TwoSurfaceExchange AF Sigma 1e 4 surfacel atlas atlas region bottom scalarfield zheight scalarvalue 3e 9 scalarside surface2 atlas atlas region top scalarfield zheight scalarvalue 6e 9 scalarside t Example spinvalve af mif Oxs_RandomSiteExchange A randomized exchange energy The Specify block has the form Specify Oxs_RandomSiteExchange name linkprob probability Amin A_lower_bound Amax A_upper_bound Each adjacent pair of cells 7 j is given linkprob probability of having a non zero e
196. h mically in Octs starts with 1 for the x y z space 2 for the z y z space 3 for the x y z space etc The conversion between the two systems is accomplished by the ordering of the regions list Examples manyregions scriptatlas mif octant mif tclshapes mif diskarray mif ellipsoid atlasproc mif 51 Oxs_EllipsoidAtlas Defines an ellipsoidal region with axes parallel to the coordinate axes This functionality can be obtained using the Oxs_ScriptAtlas class with an appropri ate Tcl script but this class is somewhat easier to use and faster The Specify block has the form Specify Oxs EllipsoidAtlas atlasname xrange xmin zmax yrange ymin ymaz zrange zmin zmar name regionname Here xmin rmaxz are coordinates in meters specifying the bounding box for the ellipsoid The layout of the Specify block is exactly the same as for the Oxs_BoxAtlas class except that in this case the named region is not the whole bounding box but rather that subvolume that is the interior of the ellipsoid inscribed inside the bounding box Points exterior to that ellipsoid are assigned to the universe region As in the Oxs_BoxAtlas case the regionname entry is optional if missing the region name is taken from the object instance name i e atlasname Example ellipsoid mif See also ellipsoid atlasproc mif and ellipsoid fieldproc mif for equivalent examples using Tcl scripts 7 3 2 Meshes Meshes
197. hat the object is prepared for any range of stages Zero is the default value for stage_count 64 when using the Tcl_script interface The stage_count value given here must be compatible with the stage_count setting in the driver Specify block q v The example above made use of two scripts one to specify the Oxs_VectorField object and one used internally by the Oxs_ScriptVectorField object But any Oxs_VectorField class may be used as in the next example Specify Oxs_StageZeeman script FileField stage_count 3 proc FileField stage set filelist field a ohf field b ohf field c ohf set spec Oxs_FileVectorField lappend spec subst atlas atlas file lindex filelist stage return spec The FileField proc yields a specification for an Oxs_FileVectorField object that loads one of three files field a ohf field b ohf or field c ohf de pending on the stage number Specifying applied fields from a sequence of files is common enough to warrant a simplified interface This is the purpose of the files parameter Specify Oxs_StageZeeman files field a ohf field b ohf field c ohf This is essentially equivalent to the preceding example with two differences First stage count is not needed because 0xs_StageZeeman knows the length of the list of files You may specify stage_count but the default value is the length of the files list This is in contrast to the default value of 0 when using the script
198. he MIF Parameter command to set variables from the command line for use inside the MIF input file Variables in Tcl are evaluated i e value substituted by prefixing the variable name with the symbol For example if cellsize is a variable holding the value 5e 9 then cellsize evaluates to 5e 9 Unfortunately there are complications in using variables inside Specify blocks Consider this simple example Parameter cellsize 5e 9 Specify Oxs_RectangularMesh BadExample comment NOTE THIS DOESN T WORK cellsize cellsize cellsize cellsize atlas atlas This doesn t work because the curly braces used to set off the Specify initialization string also inhibit variable substitution There are several ways to work around this but the easiest is usually to embed the initialization string inside a subst substitution command Parameter cellsize 5e 9 Specify Oxs_RectangularMesh GoodExample subst comment NOTE This works cellsize cellsize cellsize cellsize atlas atlas Here the square brackets and cause Tcl to perform command substitution i e execute the string inside the square brackets as a Tcl command in this case the subst command See the Tcl documentation for subst for details but the default usage illustrated above performs variable command and backslash substitutions on the argument string One more example this time involving both variable and command substitution
199. he current stage index by either typing the desired stage number counting from 0 into the Stage entry box or by moving the associated slider e Output options can be changed and new output windows opened The Send button in the Oxsii Schedule subwindow is used to interactively send output to the selected Output Destination pair STEP 4 Exit OOMMF e Individual OOMMF applications can be terminated by selecting the File Exit menu item from their interface window e Selecting File Exit on the mmLaunch window will close the mmLaunch window and also the interface windows for any mmArchive mmSolve2D and Oxsii applications However those applications will continue to run in the background and their interfaces may be re displayed by starting a new mmLaunch instance 25 e To automatically kill all OOMMF applications select the File Exit All OOMMEF option from the mmLaunch menu bar 26 4 OOMME Architecture Overview Before describing each of the applications which comprise the OOMMF software it is helpful to understand how these applications work together OOMMF is not structured as a single program Instead it is a collection of programs each specializing in some task needed as part of a micromagnetic simulation system An advantage of this modular architecture is that each program may be improved or even replaced without a need to redesign the entire system The OOMMF programs work together by providing services to one anothe
200. he first is the Tcl shell to use the second is an absolute path to the OOMMF boot strap program on the master machine the third is connection information needed by the batchslave application the fourth is the path to the OOMMF root directory on the master machine and the last is interpreted as a single percent batchmaster automatically ap pends the argument amp to the lt spawn command gt so that the slave applications are launched in the background To launch batchslave on a remote host use rsh in the spawn command e g 120 FILE simpletask tcl This is a sample batch task file Usage example tclsh oommf tcl batchmaster simpletask tcl Form task list TaskInfo AppendTask A BatchTaskRun taskA mif TaskInfo AppendTask B BatchTaskRun taskB mif TaskInfo AppendTask C BatchTaskRun taskC mif Figure 1 Sample task script simpletask tcl TaskInfo AppendSlave 1 exec rsh foo tclsh oommf oommf tcl batchslave tk 0 connect_info batchsolve tcl This example assumes tclsh is in the execution path on the remote machine foo and OOMMF is installed off of your home directory In addition you will have to add the machine foo to the host connect list with TaskInfo ModifyHostList foo and batchmaster must be run with the network interface specified as the server host instead of the default localhost e g tclsh oommf tcl batchmaster multitask tcl bar where bar is the name of the local machine This
201. he host server explicitly in order to control the host server port address Launching The launchhost command line is tclsh oommf tcl launchhost standard options port where 170 port Requested port number for host server to listen on For non privileged users this usually has to be larger than 1024 or the special value 0 which signals the host server to open on a random unused port On success launchhost writes the host port number actually used to stdout As described in the OOMMF architecture documentation Sec 4 the host server host ser vice directory plays a vital role in allowing various OOMMF applications to communicate with one another To work the host server port number must be known to all OOMMF ap plications Typically this port number is determined by the Net_Host port setting in the file oommf config options tcl although this setting may be overridden by the environment variable OOMMF_HOSTPORT In batch mode settings however it can occur that one wants to run multiple concurrent but independent OOMMF sessions on a single machine One way to accomplish this is to set the environment variable OOMMF_HOSTPORT to distinct values in each session A difficulty here is the bookkeeping necessary to insure that each session really gets a distinct value Using launchhost with port set to zero provides a straightforward solution to this problem For example consider the Bourne shell script bin sh OOMMF_HOSTPORT
202. he safe Tcl restrictions outlined above a number of additional commands are available in MIF 2 1 files Specify ClearSpec Destination Ignore OOMMFRootDir Parameter Random RandomSeed Report ReadFile RGlob and Schedule Specify An Oxs simulation is built as a collection of Oxs_Ext Oxs Extension objects In general Oxs_Ext objects are specified and initialized in the input MIF 2 1 file using the Specify command making Specify blocks the primary component of the problem definition The Specify command takes two arguments the name of the Oxs_Ext object to create and an initialization string that is passed to the Oxs Ext object during its construction The objects are created in the order in which they appear in the MIF file Order is important in some cases for example if one Oxs_Ext object refers to another in its initialization string then the referred to object must precede the referrer in the MIF file Here is a simple Specify block Specify Oxs_EulerEvolve foo alpha 0 5 start_dm 0 01 The name of the new Oxs_Ext object is Oxs EulerEvolve foo The first part of this name up to the colon is the the C class name of the object This must be a child of the Oxs_Ext class Here Oxs_EulerEvolve is a class that integrates the Landau Lifshitz ODE using a simple forward Euler method The second part of the name i e the part following the colon is the instance name for this particular instance of the object In gene
203. he spawn command so that all slave applications are launched in the background The communication protocol between batchmaster and batchslave is evolving and is not described here Check the source code for the latest details 10 2 2 3 Batch Task Scripts The application batchmaster creates an instance of a BatchTask0bj object with the name TaskInfo The task script uses method calls to this object to set up tasks to be performed The only required call is to the AppendTask method e g TaskInfo AppendTask A BatchTaskRun taskA mif This method expects two arguments a label for the task here A and a script to accom plish the task The script will be passed across a network socket from batchmaster to a slave application and then the script will be interpreted by the slave In particular keep in mind that the file system seen by the script will be that of the machine on which the slave process is running This example uses the default batchsolve tcl procs to run the simulation defined by the taskA mif MIF 1 x file If you want to make changes to the MIF problem specifications on the fly you will need to modify the default procs This is done by creating a slave initialization script via the call TaskInfo SetSlaveInitScript lt insert script here gt The slave initialization script does global initializations and also usually redefines the SolverTaskInit proc optionally the BatchTaskIterationCallback BatchTaskRelaxCallback
204. hive Sec 14 If aveMflag is true 1 then the output values are scaled to lie in the range 1 1 where the extreme values are obtained only at saturation i e all the spins are aligned If aveMflag is false 0 then the output is in A m The default setting is 1 In the older MIF 2 1 format the driver Specify block supports three additional val ues basename scalar_output_ format and vector field output format In the MIF 2 2 format these output controls have been moved into the SetOptions block See the SetOptions Sec 17 2 2 documentation for details Oxs_TimeDriver provides 11 scalar outputs and 2 vector field outputs The scalar outputs are e Stage current stage number counting from 0 79 e Stage iteration number of successful evolver steps in the current stage e Iteration number of successful evolver steps in the current simulation e Simulation time Landau Lifshitz Gilbert evolution time in seconds e Last time step The size of the preceding time step in seconds e Mx mx magnetization component in the x direction averaged across the entire simulation in A m Mx or normalized units mx depending on the setting of the normalize_aveM_output option e My my magnetization component in the y direction averaged across the entire simulation in A m My or normalized units my depending on the setting of the normalize_aveM_output option e Mz mz magnetization component in the z direction averaged ac
205. hnology by employees of the Federal Government in the course of their official duties Pursuant to Title 17 United States Code Section 105 this software is not subject to copyright protection and is in the public domain OOMMEF is an experimental system NIST assumes no responsibility whatsoever for its use by other parties and makes no guarantees expressed or implied about its quality reliability or any other characteristic We would appreciate acknowledgement if the software is used When referencing OOMMF software we recommend citing the NIST technical report M J Donahue and D G Porter OOMMEF User s Guide Version 1 0 NISTIR 6376 National Institute of Standards and Technology Gaithersburg MD Sept 1999 Commercial equipment and software referred to on these pages are identified for informa tional purposes only and does not imply recommendation of or endorsement by the National Institute of Standards and Technology nor does it imply that the products so identified are necessarily the best available for the purpose 1 Overview of OOMME The goal of the OOMMF Object Oriented Micromagnetic Framework project in the Infor mation Technology Laboratory ITL at the National Institute of Standards and Technology NIST is to develop a portable extensible public domain micromagnetic program and asso ciated tools This code will form a completely functional micromagnetics package but will also have a well documented fle
206. hreads that will be run by the Oxs 3D solver programs oxsii and boxsi You can modify the default by editing the oommf_thread_count value in the config platforms file for your platform You can override the default at run time by setting the environment variable OOMMF_THREADS or by using the command line option threads to oxsii and boxsi Some multi processor machines have a non uniform memory architecture NUMA which means that although each processor can access all of system memory some parts of memory can be accessed faster than others Typically this is accomplished by dividing the system memory and processors into nodes Memory accesses within a node are faster than accesses between nodes and depending on the architecture access latency and bandwidth may be different between different node pairs Examples of machines with NUMA include some multi processor AMD Opteron and Intel Nehalem Xeon boxes Computer programs such as OOMMF can run on NUMA machines without making any special allowances for the memory architecture However a program that is written to take advantage of the faster local intra node memory accesses can sometimes run significantly faster OOMMF contains NUMA aware code but this code is highly operating system spe cific At present OOMMF can be built with NUMA support only on Linux 32 and 64 bit systems To do this you must install the operating system NUMA support packages nu mactl and numactl devel
207. ically deleted but this is not guaranteed if the program terminates abnormally Tk Requirement any2ppm uses the Tk image command in its processing This requires that Tk be properly initialized which in particular means that a valid display must be available This is not a problem on Windows where a desktop is always present but on Unix this means that an X server must be running The Xvfb virtual framebuffer can be used if desired Xvfb is an X server distributed with X11R6 that requires no display hardware or physical input devices 16 2 Making Data Tables from Vector Fields avf2odt The avf2odt program converts rectangularly meshed vector field files in any of the recognized formats OVF VIO see Sec 19 into the ODT 1 0 Sec 18 data table format Irregular meshes are not supported by this command Note that any OVF file using the irregular meshtype is considered to be using an irregular mesh even if the mesh nodes do in fact lie on a rectangular grid Launching The avf2odt launch command is tclsh oommf tcl avf2odt standard options average lt space plane line point ball gt axis lt xlylz gt ball_radius brad defaultvals lt 0 1 gt filesort method headers lt full collapse none gt index label units valexpr ipat pattern normalize lt 0 1 gt numfmt fmt onefile outfile opatexp regexp opatsub sub region xmin ymin zmin xmax ymax zmax rregion rxmin rymin rzmin
208. iform 90 45 Initial magnetization routine and parameters HEHEHE HHH EXPERIMENT PARAMETERS HHHHHHHHHH HEHEHE Field Range Start_field Stop_field Steps Field Range 05 01 0 05 01 0 100 Field Range 05 01 0 05 01 0 100 Field Type Multi 4 7 Ribbon 1 0 1 0e 6 0 25e 6 1 0e 6 1e 9 7 Ribbon 1 0 0 0 25e 6 0 1e 9 9 Tie 100 0 0 0 12e 6 0 5e 6 0 13e 6 0 5e 6 8e 9 1 Uniform The above positions ribbons of positive charge along the upper and lower edges with strength Ms applies a large 100 Ms field to the center cells and also applies a uniform field across the sample stepped from 05 01 0 to 05 01 0 Tesla and back in approximately 0 001 T steps HH H H HF Default Control Point Spec torque 1e 6 Assume equilibrium has been reached and step the applied field when the reduced torque mxh drops below 1e 6 HHHHHHHHHHHHHHH OUTPUT SPECIFICATIONS HHHHHHHHHHHHHHHHH Base Output Filename samplerun Magnetization Output Format binary 8 Save magnetization states in binary format with full 8 byte precision 217 HHHHHHHHHHHHHHHHHHHH MISCELLANEOUS HHHHHHHHHHHHHHHHHHEEEH Randomizer Seed 1 Random number generator seed User Comment Example MIF 1 1 file with lots of comments Figure 9 Example MIF 1 1 file 17 4 MIF 1 2 The MIF 1 2 format is a minor modification to the MIF 1 1 format which supports limited 3D problem specification It can be read by the Oxs 3D solvers an
209. igure brings up a dialog box through which the user may control many features of the vector field display Vectors in the vector field may be displayed as arrows pixels or both The Arrow and Pixel buttons in the Plot type column on the left of the dialog box enable each type of display Columns 2 4 in the Configure dialog box control the use of color Both arrows and pixels may be independently colored to indicate some quantity The Color Quantity column controls which scalar quantity the color of the arrow or pixel represents Available color quantities include vector x y and z components total vector magnitude slice depth and angles as measured in plane from a fixed axis On regularly gridded data the vector field divergence is also available for display The assignment of a color to a quantity value is determined by the Colormap selected Colormaps are labeled by a sequence of colors that are mapped across the range of the selected quantity For example if the Red Black Blue colormap is applied to the Color Quantity z then vectors pointing into the ry plane z lt 0 are colored red those lying in the plane z 0 are colored black and those pointing out of the plane z gt 0 are colored blue Values between the extremes are colored with intermediate colors selected using a discretization determined by the of Colors value This value governs the use of potentially limited color resources and can be used to achieve some
210. ike so file 3 noexpand 2 5 file expand The noexpand keyword placed at the end of a list disables all group expansion in that list Although it is an unlikely example if one had a flat i e non grouped list with last element expand then one would have to disable the grouping mechanism that would otherwise be invoked by appending noexpand to the list In flat lists generated by program code it is recommended to append noexpand just to be certain that the list is not expanded As a matter of nomenclature standard i e flat lists and single values are also considered grouped lists albeit trivial ones Any Oxs object that accepts grouped lists in its Specify block should explicitly state so in its documentation 17 1 3 4 Comments The standard Tcl commenting mechanism treats all text running from an initial symbol through to the end of a line as a comment You may note in the above examples that newlines are treated the same as other whitespace inside the curly braces delimiting the Specify initialization string Because of this and additional reasons Tcl comments cannot be used inside Specify blocks Instead by convention any label value pair where label is comment is treated as a comment and thrown away For example Specify Oxs_UniaxialAnisotropy axis 1 00 comment Ki 4500e3 K1 530e3 comment 530e3 J m 3 is nominal for Co Pay attention to the difference between comment used h
211. iler and system documentation for details Using the Cygwin toolkit The Cygwin Project is a free port of the GNU development environment to Windows which includes the GNU C compiler g OOMMEF has been successfully built and tested within the Cygwin environment sample configuration files config names cygtel tcl and config platforms cygtel tcl are included in the OOMMF distribution IMPORTANT Use a standard Windows build of Tcl Tk e g the ActiveTcl release when configuring building and launching OOMMF software As of this writing Oct 2004 the tclsh distributed with Cygwin i e usr bin tclsh has problems involving sockets that make it unsuitable for use with OOMMF Unfortunately standard Windows versions of Tcl are not acquainted with the Cygwin POSIX style pathnames so in many cases you will have to use Windows style pathnames instead Note that OOMMF software determines whether it is running under Cygwin by exam ining the environment variables OSTYPE and TERM If either is set to a value beginning with cygwin the Cygwin environment is assumed If you are using the Cygwin environ ment with different values for both OSTYPE and TERM you will have to modify the config names cygtel tcl file accordingly http www cygwin com Uhttp www activestate com Products ActiveTcl 16 Using Borland C OOMME has been successfully built and tested using the Borland C command line compiler version 5 5 However a couple prep
212. iles Multiple SetOptions blocks are allowed Label values specified in one SetOption block may be overwritten by a later SetOption block Output formats for a given output are set during the processing of the Specify block for the enclosing Oxs Ext object Therefore one can specify different formats for outputs in different Oxs_Ext objects by strategic placement of SetOptions blocks Additional label names may be added in the future and may be Oxs_Ext class de pendent At present there is no checking for unknown label names but that policy is subject to change An example SetOptions block SetOptions basename fubar scalar_output_format 12g scalar_field_output_format text 4g scalar_field_output_meshtype irregular vector_field_output_format binary 4 EvalScalarField This command allows access in a MIF file to values from a scalar field defined in a preceding Specify block For example Oxs_AtlasScalarField Ms atlas atlas default_value 0 values Adisks 520e3 Bdisks 520e3 H set Ms_a EvalScalarField Ms 50e 9 20e 9 2e 9 The four arguments to EvalScalarField are a reference to the scalar field here Ms and the three coordinates of the point where you want the field evaluated The coor dinates are in the problem coordinate space i e in meters 203 EvalVectorField This command is the same as the EvalScalarField command except that the field reference is to a vector field and the return value is
213. imulation from paused point with Run or Relax Field Apply the previous field again Field Apply the next field in the list e Output options can be changed and new output windows opened STEP 3b Run a 3D problem Launch solver e On the mmLaunch window click on the Oxsii button to launch an instance of the program Oxsii e Wait for the new solver instance to appear in the Threads column in the mm Launch window 23 e Check the box next to the Oxsii entry in the Threads column A window contain ing an Oxsii interface will appear Load problem e On the Oxsii window select the File Load menu option A Load Problem dialog box will appear On this window Double click in the Path subwindow to change directories Several sample problems can be found in the directory oommf app oxs examples To load a problem double click on a mif file e g stdprobl mif from the list above the Filter subwindow The native input format for the 3D solver is the MIF 2 1 Sec 17 1 format which must be composed by hand using a plain text editor See the Oxs_Ext Child Class Sec 7 3 documentation for additional details However MIF 1 1 i e 2D problem files are readable by Oxsii or may be converted to the MIF 2 1 format using the command line tool mifconvert Sec 16 11 mmProbEd also supports an extension to the MIF 1 1 format namely MIF 1 2 which provides limited 3D functionality MIF 1 2 files may also be rea
214. in config names recognizes your platform type As an example to add the platform name foo to OOMMF s vocabulary of platform names create the file config names foo tcl The simplest way to proceed is to copy an existing file in the directory config names and edit it to recognize your platform The files in config names include Tcl code like this Oc_Config New _ string tolower file rootname file tail info script In this block place the body of a Tcl proc which returns 1 if the machine on which the proc is executed is of the platform type identified by this file and which returns 0 otherwise The usual Tcl language mechanism for discovering details about the machine on which the proc is running is to consult the global Tcl variable tcl_platform See the existing files for examples or contact the OOMMF HH H HH HOH OF developers for further assistance After creating the new platform name file config names foo tcl you also need to create a new platform file config platforms foo tcl A reasonable starting point is to copy the file config platforms unknown tcl for editing Contact the OOMMF developers for assistance Please consider contributing your new platform recognition and configuration files to the OOMMEF developers for inclusion in future releases of OOMMEF software Resolving platform name conflicts Ifthe script oommf tcl platform reports Mul tiple platform names are compatible with your compute
215. in the rectangle will be tied to the direction of that field This routine ignores the NAF OneFile filename multiplier Read B field in Tesla in from a file Each value in the file is multiplied by the multiplier value on input This makes it simple to reverse field direction use 1 for the multiplier or to convert H fields to B fields use 1 256637e 6 The input file may be any of the vector field file types recognized by mmDisp The input dimensions will be scaled as necessary to fit the simulation grid with zeroth order interpolation as necessary This routine ignores the NAF FileSeq filename procname multiplier This is a generalization of the OneFile routine that reads in fields from a sequence of files Here filename is the name of a file containing Tcl code to be sourced during problem initialization and procname is the name of a Tcl procedure defined in filename which takes the nominal B field components in Tesla and field step count values as imports 4 values total and returns the name of the vector field file that should be used as the applied B field for that field step The B field units in the vector field file should be Tesla Multi routinecount paramlcount namel param1 param2 param2count name2 param1 param2 Allows a conglomeration of several field type routines All entries must be on the same logical line i e end physical lines with continuation characters as
216. in the simulation discretization mesh The proc returns a value either scalar or vector which is interpreted as some property of the simulation at that point in space such as saturation magnetization anisotropy properties or an external applied field Here is an example proc that may be used to set the initial magnetization configuration into an approximate vortex state with a central core in the positive z direction proc Vortex x_rel y_rel z_rel set xrad expr x_rel 0 5 set yrad expr y_rel 0 5 set normsq expr xrad xrad yrad yrad if normsq lt 0 0125 return 0 0 1 return list expr 1 yrad xrad 0 The return value in this case is a 3D vector representing the spin direction at the point x_rel y_rel z_rel Procs that are used to set scalar properties such as saturation mag netization M return a scalar value instead But in both cases the import argument list specifies a point in the simulation mesh In the above example the import point is specified relative to the extents of the simulation mesh For example if x_rel were 0 1 then the x coordinate of the point is one tenth of the way between the minimum z value in the simulation and the maximum z value In all cases x_rel will have a value between 0 and 1 192 In most support proc examples relative coordinates are the most flexible and easiest representation to work with However by convention scripting Oxs_Ext classes also support abso
217. ing When the problem is fully loaded more buttons appear Check Scheduled Outputs For each desired output TotalField Magnetization and or DataTable spec ify the frequency of update 1 Check desired output This will exhibit the possible output destinations un der the Destination Threads heading Output applications such as mmDisp mmGraph and or mmDataTable must be running to appear in this list 2 Check the box next to the desired Destination Thread This will exhibit Schedule options 3 Choose a schedule x Iteration fill in number and check the box x ControlPoint fill in number and check the box x Interactive whenever you click corresponding Interactive output button Start calculation e On the mmSolve2D window start the calculation with Run which runs until problem completion or Relax which runs until the next control point is reached e If you requested mmDataTable output check the boxes for the desired quantities on the mmDataTable window under the Data menu so that they appear and are updated as requested in your schedule e Similarly check the box for the desired X Y1 and Y2 quantities on the mmGraph window s under the X Y1 and Y2 menus 22 Save results e Vector field data magnetization and effective field may be interactively written to disk using mmDisp or may be automatically saved via scheduled output to mmArchive For example to save the magnetization state at each control poin
218. ing describe the Tcl shell running the oommf tcl 6 script After that the tclsh OOMMF subgroup describes the Tcl shell that OOMMF will launch when it needs to run vanilla Tcl scripts If the OOMMF binaries have been built then there will also be a filtersh subgroup which describes the augmented Tcl shell used to run many of the OOMMF support scripts All of these shells should report the same version bitness and threading information If OOMMF can t find tclsh or if it finds the wrong one you can correct this by setting the environment variable OOMMF_TCLSH to the absolute location of tclsh For information about setting environment variables see your operating system documentation Following the Tcl shell information the tclConfig sh lines report the name of the configuration file installed as part of Tcl if any Conventional Tcl installations on Unix systems and within the Cygwin environment on Windows have such a file usually named tclConfig sh The Tcl configuration file records details about how Tcl was built and where it was installed On Windows platforms this information is recorded in the Windows reg istry so it is normal to have oommf tcl platform report none found If oommf tcl platform reports none found but you know that an appropriate Tcl configuration file is present on your system you can tell OOMMF where to find the file by setting the environ ment variable OOMMF_TCL_CONFIG to its absolute
219. ing quotes For example numanodes 2 4 6 or numanodes 2 4 6 Threads are assigned to the nodes in order in round robin fashion The user can ei ther assign all the system nodes to the Boxsi process or may restrict Boxsi to run on a subset of the nodes In this way the user may reserve specific processing cores for other processes or other instances of Boxsi Although it varies by system typically there are multiple processing cores associated with each memory node If the keyword auto is selected then the threads are assigned to a fixed node sequence that spans the entire list of memory nodes If the keyword none is selected then threads are not tied to nodes by Boxsi but are instead assigned by the operating system In this last case over time the operating system is free to move the threads among processors In the other two cases each thread is tied to a particular node for the lifetime of the Boxsi instance See also the discussion on threading considerations below The default value for nodes is none which allows the operating system to assign and move threads based on overall system usage This is also the behavior obtained when the Oxs build is not NUMA aware On the other hand if a machine is dedicated primarily to running one instance of Boxsi then Boxsi will likely run fastest if the 41 thread count is set to the number of processing cores on the machine and nodes is set to auto If you want to run
220. interface If stage_count is set larger than the file list then the last file is repeated as necessary to reach the specified size The second difference is that no Oxs_Atlas is specified when using the files interface The Oxs_FileVectorField object spatially scales the field read from the file to match a specified volume Typically a volume is specified by explicit reference to an atlas but with the files interface to Oxs_StageZeeman the file fields are implicitly scaled to match the whole of the meshed simulation volume This is the most common case to obtain a different spatial scaling use the script interface as illustrated above with a different atlas or an explicit x y z range specification 65 The list_of_files value is interpreted as a grouped list See the notes in Sec 17 1 3 3 for details on grouped lists The remaining Oxs_StageZeeman parameter is multiplier The value of this parameter is applied as a scale factor to the field magnitude on a point by point basis For example if the field returned by the O0xs_VectorField object were in Oe instead of the required A m then multiplier could be set to 79 5775 to perform the conversion The direction of the applied field can be reversed by supplying a negative multiplier value Examples sliding mif slidingproc mif rotatestage mif rotatecenterstage mif 7 3 4 Evolvers Evolvers are responsible for updating the magnetization configuration from one step to the next There are t
221. interval from the start point i e the stop point from the previous line minimization process is less than line_minimum_relwidth In either case the stop point i e the effective minimum is taken to be the endpoint of the final interval having smaller energy The default value for min_prec_angle is 5 degrees and the default value for relwidth is 1 This latter setting effectively disables the line_minimum_relwidth control which should generally be used only as a secondary control If the bracketing process is unsuccessful i e the check for bracketed energy minimum failed at the maximum bracket interval size allowed by maximum_bracket_step then the maximum bracket endpoint is accepted as the next point in the minimization iteration Once the line minimum stop point has been selected the next iteration begins with selection of a new line direction as described above except in the case where the stop point was not obtained as an actual minimum but rather by virtue of satisfying the maximum_bracket_step constraint In that case the orthogonal line sequence is reset in the same manner as when the gradient_reset_angle or gradient_reset_count controls are triggered and the next line direction is taken directly from the energy gradient There are several factors to bear in mind when selecting values for the parame ters minimum_bracket_step maximum_bracket_step and line_minimum_relwidth If minimum bracket_step is too small then it may
222. iptOrientScalarField Oxs_AffineOrientScalarField Oxs_AffineTransformScalarField Oxs_ImageScalarField 45 e Vector Field Objects Oxs_AtlasVectorField Oxs_FileVectorField Oxs_PlaneRandomVectorField Oxs_RandomVectorField Oxs_ScriptVectorField Oxs_UniformVectorField Oxs_ScriptOrientVectorField Oxs_AffineOrientVectorField Oxs_AffineTransformVectorField Oxs_MaskVectorField Oxs_ImageVectorField e MIF Support Classes Oxs_LabelValue 7 3 1 Atlases Geometric volumes of spaces are specified in Oxs via atlases which divide their domain into one or more disjoint subsets called regions Included in each atlas definition is the atlas bounding box which is an axes parallel rectangular parallelepiped containing all the regions There is also the special universe region which consists of all points outside the regions specified in the atlas The universe region is not considered to be part of any atlas and the universe keyword should not be used to label any of the atlas regions The most commonly used atlas is the simple Oxs_BoxAtlas For combining multiple atlases use Oxs_MultiAtlas Oxs_BoxAtlas An axes parallel rectangular parallelepiped containing a single region that is coterminous with the atlas itself The specify block has the form Specify Oxs_BoxAtlas atlasname xrange smin xmax yrange ymin ymax zrange zmin zmar name regionname where gmin maz are coordinates in meters specifying the extents of the volume
223. is 47 black and grey100 is white Alternatively one may use any of the symbolic names defined in the oommf config colors config file such as red white and skyblue When comparing symbolic names spaces and capitalization are ignored The list of symbolic names can be extended by adding additional files to the Color filename option in the options tcl customization file Sec 2 3 2 Finally one color in the colormap list may optionally be the special keyword default All pixels that don t match any of the other specified colors as determined by the matcherror option are assigned to region paired with default Each of the specified colors should be distinct but the region names are allowed to be repeated as desired The region names may be chosen arbitrarily except the special keyword universe is reserved for points not in any of the regions This includes all points outside the atlas bounding box defined by the xrange yrange zrange entries but may also include points inside that boundary Pixels in the image are assigned to regions by comparing the color of the pixel to the list of colors specified in colormap If the pixel color is closer to a colormap color than max_color_distance then the colors are considered matched If a pixel color matches exactly one colormap color then the pixel is assigned to the corresponding region If a pixel color matches more than one colormap color the pixel is assigned to the region corre
224. is large enough that a portion of the vector field lies outside the 139 display window scrollbars appear that may be used to translate the vector field so that different portions are visible in the display window On systems that have a middle mouse button clicking the middle button on a point in the display window translates the vector field so that the selected point is centered within the display window mmDisp remembers the previous zoom value and data scale values To revert to the previous settings the user may hit the ESC key This is a limited Undo feature Below the data scale and zoom controls in the control bar is the slice center selection control This will be labeled Z slice X slice or Y slice depending on which view axis is selected The thickness of the slice can be set from the Options Configure dialog box The final item under the Options menu is the Options Lock size checkbutton By default when the display is rotated in plane the width and height of the viewport are interchanged so that the same portion of the vector field remains displayed Selecting the Options Lock size checkbutton disables this behavior and also other viewport changing operations e g display wrap Several keyboard shortcuts are available as alternatives to menu or mouse based opera tions These are in addition to the usual keyboard access to the menu The effect of a key combination depends on which subwindow of mmDisp is active Th
225. is zpixelspan Identical interpreta tion and behavior as the corresponding arrow span elements but with regards to pixel display The print config array controls printing defaults as displayed in the File Print dialog box orient Paper orientation either landscape or portrait paper Paper type letter legal A4 or A3 hpos vpos The horizontal and vertical positioning on the printed page Valid values for hpos are left center or right and for vpos are top center or bottom units Units that the margin and print area dimensions are measured in either in or cm tmargin lmargin Top and left margin size measured in the selected units pwidth pheight Output print area dimensions width and height measured in the selected units The output will be scaled to meet the more restrictive dimension In particular the x y scaling ratio remains 1 1 144 croptoview Boolean value either 0 or 1 If 1 true then the print output is cropped to display only that portion of the vector field that is visible in the display window If 0 then the display is ignored and the output is scaled so that the entire vector field is printed If any of the above elements are set in multiple configuration files then the last value read takes precedence Details The selection of vectors for display determined by the Subsample value differs depending on whether or not the data lie on a regular grid If so Subsample takes integer values and deter
226. isk space 3 4 10 display 34 107 115 rsh 117 Tcl Tk 3 TCP IP 3 Tk 34 107 115 154 Tk 8 0 153 sampling 142 saturation magnetization 210 Schedule command MIF 186 segment block 221 self magnetostatic see demagnetization server 27 services 27 SetOptions command MIF 79 81 202 simulation 2D restarting 108 114 simulation 3D restarting 36 41 simulation 2D 1 107 114 236 control point 23 109 113 119 121 214 equilibrium 23 interactive control 22 23 110 115 iteration 214 mxh 110 214 216 scheduling 117 122 termination 111 115 time 109 214 simulation 3D 1 batch 39 interactive 34 interactive control 24 25 stage 25 sockets 232 Specify attributes MIF 192 Specify block MIF 181 Specify comments MIF 191 Specify conventions MIF 187 Specify initialization string MIF 187 Specify support procs MIF 192 Specify user scalar outputs MIF 194 standard options 30 31 step size 109 task script 117 119 Tcl list 187 209 TCP IP 3 27 temporary files 7 threads 22 24 33 37 39 42 108 109 threads parallel see parallelization time step 109 torque see simulation mxh total field see field effective URL 151 user ID 27 33 variable substitution MIF 197 vortex 213 working directory 5 9 28 29 33 115 122 Xvfb see application Xvfb 241
227. it the Material Name Ms A K1 and Anisotropy Type values as desired and hit the Add button The Damp Coef and Anistropy Init settings are not affected by the Material Types selection The Material Name entry will appear in red if it does not match any name in the Material Types list or if the name matches but one or more of the material values differs from the corresponding value as stored in the Material Types list You can manage the Material Types list with the Replace and Delete buttons or by directly editing the file oommf app mmpe 1local materials follow the format of other entries in that file The format is the same as in the default oommf app mmpe materials file included with the OOMMF distribution 103 The menu selection File Exit terminates the mmProbEd application The menu Help provides the usual help facilities 104 9 Micromagnetic Problem File Source FileSource Export tmp oommf app mmpe examples prob1 mif Overview The application FileSource provides the same service as mmProbEd Sec 8 supplying MIF 1 x problem descriptions to running mmSolve2D micromagnetic solvers As the MIF specification evolves mmProbEd may lag behind There may be new fields in the MIF specification that mmProbEd is not capable of editing or which mmProbEd may not pass on to solvers after loading them in from a file To make use of such fields a MIF file may need to be edited by hand using a general purpose text editor FileS
228. k both the User variables and the System variables settings You will need to launch a new shell command prompt for the changes to take effect 2 Create Borland compatible Tcl and Tk libraries The import libraries distributed with Tcl Tk release 8 0 3 and later are not com patible with the Borland C linker However the command line utility coff2omf which is distributed with the Borland compiler can be used to create suitable libraries from the Tcl Tk lib s In the Tcl Tk library directory typically C Tcl lib or C Program Files Tcl lib issue the following commands coff2omf tcl84 lib tcl84bc lib coff2omf tk84 lib tk84bc lib Here tc184 1ib and tk84 1ib are the input libraries in COFF format and tc184bc lib and tk84bc 1ib are the new libraries in OMF format If coff2omf doesn t work you can try creating the necessary import libraries directly from the Tcl Tk DLL s From the Tcl Tk library directory issue the following com mands 17 impdef a tcl84bc def bin tc1l84 d11 implib tcl84bc 1lib tcl84bc def This creates the Borland compatible import library tcl184bc 1ib Repeat with tk in place of tcl to create tk84bc 1lib The a switch requests impdef to add a leading underscore to function names This is sufficient for the DLL s shipped with Tcl Tk 8 4 but other releases may require additional tweaking The module definition file output by impdef e g tcl84bc def above is a pl
229. l fconfigure command Refer to the Tcl documenta tion for details Specifying image causes the input file to be read as an image file The file will be read directly if it in the PPM P3 text PPM P6 binary or uncompressed BMP formats otherwise it is filtered through the OOMMF any2ppm Sec 16 1 pro gram Note that any2ppm requires Tk and Tk requires a display The input file is converted into a string that mimics a PPM P3 text file minus the leading P3 In par ticular after conversion the first 3 whitespace separated values are image width height and maxvalue followed by an array of 3 x width x height values where each triplet corresponds to the red green and blue components of an image pixel sequenced in normal English reading order Each component is in the range 0 maxvalue This out put contains no comments and may be treated directly as a Tcl list The floatimage option is very similar to the image option except that the third value i e maxvalue in the resulting string is always 1 and the succeeding red green and blue values are floating point values in the range 0 1 In all cases the return value from the ReadFile command is a string corresponding to the contents of the possibly translated file For example eval ReadFile extra_mif_commands tcl can be used to embed a separate Tcl file into a MIF 2 1 file 184 Here s a more complicated example that uses a color image file to create a vector
230. l_time script SineField proc SineField total_time set PI expr 4 atan 1 set Amp 800 0 set Freq expr 1e9 2 PI set Hx expr Amp sin Freq total_time set dHx expr Amp Freq cos Freq total_time return list Hx 0 0 dHx 0 0 Examples acsample mif pulse mif rotate mif varalpha mif yoyo mif Oxs_TransformZeeman Essentially a combination of the Oxs_FixedZeeman and Oxs_ScriptUZeeman classes where an applied field is produced by applying a spatially uniform but time and stage varying linear transform to a spatially vary ing but temporally static field The transform is specified by a Tcl script The Specify block has the form Specify Oxs_TransformZeeman name field vector_field_spec type transform_type script Tcl_script script_args args_request multiplier multiplier stage_count number_of_stages 61 The field specified by vector_field_spec is evaluated during problem initialization and held throughout the life of the problem On each iteration the specified Tcl script is called once Appended to the script are the arguments requested by script_args as explained in the User Defined Support Procedures section Sec 17 1 3 6 of the MIF 2 file format documentation The value for script_args should be a subset of stage stage_time total_time The default value for script_args is the complete list in the aforementioned order The time arguments are specified in seconds The script return valu
231. larMesh mesh cellsize 5e 9 5e 9 5e 9 atlas WorldAtlas Magnetocrystalline anisotropy block The setting for K1 500e3 J m 3 implicitly creates an embedded Oxs_UniformScalarField object Oxs_RandomVectorField is an explicit embedded Oxs_Ext object Specify Oxs_UniaxialAnisotropy K1 530e3 axis Oxs_RandomVectorField min_norm 1 max_norm 1 Homogeneous exchange energy in J m This may be set from the command line with an option like parameters A 10e 12 If not set from the command line then the default value specified here 13e 12 is used Parameter A 13e 12 Specify Oxs_UniformExchange NiFe subst A A Define a couple of constants for later use set PI expr 4 atan 1 set MUO expr 4 PI 1e 7 The Oxs_UZeeman class is initialized with field ranges in A m The following block uses the multiplier option to allow ranges to be specified in mT Use the Tcl subst command to enable variable and command substitution inside a Specify block Specify Oxs_UZeeman AppliedField subst multiplier expr 0 001 MUO Hrange 0 0 0 10 0 O 2 10 0 0O 10 0 0O 2 0 0 0 010 0 4 199 Enable demagnetization self magnetostatic field computation This block takes no parameters Specify Oxs_Demag Runge Kutta Fehlberg ODE solver with default parameter values Specify Oxs_RungeKuttaEvolve The following procedure is used to set the initial spin configuration in the O
232. ld_y atlas octant default_value 0 0 0 values octant 0 1 0 Specify Oxs_Demag user_output name Hdemag_x source_field Field select_field 1 0 0 user_output name octant Hdemag_y source_field Field select_field octant_field_y The first user output Hdemag_x returns the z component of the demagnetization field averaged across the entire simulation volume This output will appear in DataTable output with the label Oxs Demag Hdemag_x The source_field parameter Field refers to the Field output of the surrounding Oxs_Ext object which in this case means Oxs_Demag Field The select field is 1 0 0 uniform across the simulation volume The second output octant Hdemag_y is similar but the average is of the y component of the demagneti zation field and is averaged across only the first octant of the simulation volume The 196 averaging volume and component selection are defined by the octant_field_y field object which is 0 1 0 in the first octant and 0 0 0 everywhere else The source code for user defined scalar outputs can be found in the files ext h and ext cc in the directory oommf app oxs base 17 1 4 Variable Substitution One powerful consequence of the evaluation of MIF 2 1 input files by Tcl is the ability to define and use variables For example the Oxs interfaces Oxsii Sec 7 1 and Boxsi Sec 7 2 use the parameter command line option in conjunction with t
233. le assumes that the dmc compiler and associated tools are in a directory included in your environment PATH variable After this continue with the instructions in Sec 2 2 3 Compiling and Linking Setting the TCL_LIBRARY environment variable If you encounter difficulties dur ing OOMMF start up you may need to set the environment variable TCL_LIBRARY On Windows NT Bring up the Control Panel e g by selecting Settings Control Panel off the Start menu and select System Go to the Environment tab and enter TCL_LIBRARY as the Variable and the name of the directory containing init tcl for the Value e g SystemDrive4 Program Files Tcl lib tcl8 0 Click Set and OK to finish On Windows 9x Edit the file autoexec bat Add a line such as the following set TCL_LIBRARY C Program Files Tcl lib tcl8 0 Checking tcl file association on Windows NT As part of the Tcl Tk installation files with the tcl extension are normally associated with the wish application This allows Tcl scripts to be launched from Windows Explorer by double clicking on their icon or from the NT command line without specifying the tclsh or wish shells If this is not working you may check your installation from the NT command line as follows First run the command assoc tcl This should return the file type associated with the tcl extension e g TclScript Next use the ftype command to check the command line associated with that file type e g C
234. le basename log Programmer s interface In addition to directly launching batchsolve from the command line batchsolve tcl may also be sourced into another Tcl script that provides additional control structures Within the scheduling system of OBS batchsolve tcl is sourced into batchslave which provides additional control structures that support scheduling control by batchmaster There are several variables and routines inside batchsolve tcl that may be accessed and redefined from such a wrapper script to provide enhanced functionality Global variables mif A Tcl handle to a global mms_mif object holding the problem description defined by the input MIF 1 x file solver A Tcl handle to the mms_solver object search_path Directory search path used by the FindFile proc see below Refer to the source code and sample scripts for details on manipulation of these variables Batchsolve procs The following Tcl procedures are designed for external use and or redefinition SolverTaskInit Called at the start of each task BatchTaskIterationCallback Called after each iteration in the simulation BatchTaskRelaxCallback Called at each control point reached in the simulation SolverTaskCleanup Called at the conclusion of each task FindFile Searches the directories specified by the global variable search _path for a specified file The default SolverTaskInit proc uses this routine to locate the requested input MIF file SolverTaskInit and Sol
235. lected the dialog box is also dismissed The Close button dismisses the dialog without changing the display window The next item under the Options menu is a checkbutton that toggles the display of a control bar The control bar offers alternative interfaces to some of the operations available from the Options Configure dialog box and the View menu On the left end of the control bar is a display of the coordinate axes These axes rotate along with the vector field in the display window to identify the coordinate system of the display and are color coded to agree with the pixel if active or arrow coloring A click of the left mouse button on the coordinate axes causes a counter clockwise rotation A click of the right mouse button on the coordinate axes causes a clockwise rotation To the right of the coordinate axes are two rows of controls The top row allows the user to control the subsample rate and size of displayed arrows The subsample rate may be modified either by direct entry of a new rate or by manipulation of the slider The second row controls the current data scale value and zoom spatial magnification A vertical bar in the slider area marks the default data scale value Specifying O for the data scale value will reset the data scale to the default value The spatial magnification may be changed either by typing a value in the Zoom box of the control bar or by using the mouse inside the display window A click and drag with the
236. lection feature does not work properly with irregular meshes 148 14 Data Archive mmArchive Status Opened commf small odt Overview The application mmArchive provides automated vector field and data table storage ser vices Although mmDisp Sec 13 and mmGraph Sec 12 are able to save such data under the direction of the user there are situations where it is more convenient to write data to disk without interactive control mmArchive does not present a user interface window of its own but like the Oxs solvers Sec 7 relies on mmLaunch Sec 6 to provide an interface on its behalf Because mmArchive does not require a window it is possible on Unix systems to bring down the X window server and still keep mmArchive running in the background Launching mmArchive may be started either by selecting the mmArchive button on mmLaunch by Oxsii Boxsi via a Destination command in a MIF 2 file Sec 17 1 or from the command line via tclsh oommf tcl mmArchive standard options When the mmArchive button of mmLaunch is invoked mmArchive is launched with the tk 0 option This allows mmArchive to continue running if the X window server is killed The tk 1 option is useful only for enabling the console option for debugging As noted above mmArchive depends upon mmLaunch to provide an interface The entry for an instance of mmArchive in the Threads column of any running copy of mm Launch has a checkbutton next to it This button
237. led from inside a Tcl only wrapper script Note on Tk dependence If a problem is loaded that uses a bitmap mask file Sec 17 3 3 and if that mask file is not in the PPM P3 text format then batchsolve will launch any2ppm Sec 16 1 to convert it into the PPM P3 format Since any2ppm requires Tk at the time the mask file is read a valid display must be available See the any2ppm documentation for details Output The output may be changed by a Tcl wrapper script see Sec 10 2 1 but the default output behavior of batchsolve is to write tabular text data and the magnetization state at the control point for each applied field step The tabular data are appended to the file basename odt where basename is the Base Output Filename specified in the input MIF 1 x file See the routine GetTextData in batchsolve tcl for details but at present the output consists of the solver iteration count nominal applied field B reduced average magnetization m and total energy This output is in the ODT file format 115 The magnetization data are written to a series of OVF OOMMF Vector Field files basename fieldnnnn omf where nnnn starts at 0000 and is incremented at each applied field step The ASCII text header inside each file records the nominal applied field at that step These files are viewable using mmDisp Sec 13 The solver also automatically appends the input problem specification and miscellaneous runtime information to the log fi
238. ll kill the application Long running applications that do not inherently use display widgets support disabling of Tk with tk 0 Other applications that must use display widgets are unable to run with the option tk 0 To run applications that require tk 1 on a Unix system with no display one might use Xvfb cwd directory Set the current working directory of the application console Display a console widget in which Tcl commands may be interactively typed into the application Useful for debugging nickname lt name gt Associates the specified name as a nickname for the process The string name should contain at least one non numeric character Nicknames can also be set at launch time via the Destination command Sec 17 1 2 in MIF 2 x files or after a process is running via the nickname Sec 16 14 command line application Nicknames are used by the MIF 2 x Destination command to associate Oxs output streams with particular application instances Multiple nickname options may be used to set multiple nicknames Technical detail Nickname functionality is only available to processes that connect to an account server 13http www itworld com AppDev 1461 UIR000330xvfb 30 In addition those applications which enable Tk accept additional Tk options such as display See the Tk documentation for details The bootstrap application should be infrequently used by most users The application mmLaunch Sec 6 provides a more conv
239. llustrating the composition of an object of that class with a Oxs_AffineOrientVectorField object Example sample vecreflect mif Oxs_AffineOrient VectorField This class is analogous to the Oxs_AffineOrientScalarField class page 89 The Specify block has the form Specify Oxs_AffineOrientVectorField name field vector_field_spec M matriz_entries offset off off off inverse invert_flag inverse_slack slack The interpretation of the specify block and the affine transformation is exactly the same as for the Oxs_AffineOrientScalarField class except the input field and the resulting field are vector fields instead of scalar fields As explained in the Oxs_ScriptOrientVectorField documentation the orientation transformation is applied to the import spatial coordinates only not the output vector If one wishes to rotate the output vectors then a Oxs_AffineTransformVectorField object may be applied with the opposite rotation See that section for an example Examples yoyo mif sample vecrotate mif Oxs_AffineTransform VectorField This class applies an affine transform to the output of a vector field It is similar to the Oxs_AffineTransformScalarField class page 90 except that in this case the affine transform is applied to a vector instead of a scalar The Specify block has the form Specify Oxs_AffineTransformVectorField name field vector_field_spec M matriz_entries 97 offset off off off
240. lob command q v but is restricted to the current working directory that is the directory holding the MIF file The syntax is RGlob types typelist pattern The optional typelist restricts the match to files meeting the typelist criteria The optional switch marks the end of options The one or more pattern s should be glob style patterns strings containing asterisks and question marks intended to match 185 filenames in the current working directory See the Tcl glob documentation for details on the types option and glob pattern details One use of this command is to identify files created by earlier runs of Oxs For example suppose we wanted to use the mmArchive magnetization output from the third stage of a previous MIF file with basename sample Output files are tagged by stage number here 2 since stages are counted from 0 and iteration The iteration is generally not known a priori but assuming the output files are in the same directory as the current MIF file we could use a command like to determine the name of the magnetization file If more than one magnetization state was saved for that stage then the variable file will hold a list of filenames In this case the Tcl lsort command can be used to select the one with the highest iteration number The file variable can be used in conjunction with the Oxs_FileVectorField class to import the magnetization into the new simulation for example to set th
241. lude the XCode development tools on the base OS X installation disk These tools include the GNU C compiler g Install the XCode tools onto your computer and then go back to the basic OOMMF installation instructions 20 3 Quick Start Example OOMMEFE Session STEP 1 Start up the mmLaunch window e At the command prompt when you are in the OOMMF root directory type tclsh oommf tcl The name of the Tcl shell rendered here as tclsh may vary between systems This matter is discussed in Sec 2 1 Alternatively you may launch oommf tcl using what ever point and click interface is provided by your operating system e This will bring up a small window labeled mmLaunch It will come up in background mode so you will get another prompt in your original window even before the mm Launch window appears STEP 2 Gain access to other useful windows e On the mmLaunch window check the localhost box causing a menu of user account boxes to appear Check the box corresponding to the account you want to compute on On Windows 9X systems the user account list may consist of only the faux oommf user account This gives a menu of options mmArchive to auto save scalar and vector field data mmDataTable to display current values of scalar outputs mmDisp to display vector fields mmGraph to form x y plots mmProbEd to grab modify a problem for mmSolve2D or Oxsii mmSolve2D to control the 2D solver
242. lueunit and valuemultiplier header lines is inactive OOMMF rectangular mesh v1 0 This is a comment No comments allowed in the first line Segment count 1 Number of segments Should be 1 for now Begin Segment Begin Header 223 Title Long file name or title goes here Desc Desc Desc Desc description Description tag which may be used or ignored by postprocessing programs You can put anything you want here and can have as many Desc lines as you want The comment marker is disabled in lines Fundamental mesh measurement unit Treated as a label mesh unit nm meshtype rectangular xbas ybas zbas xste yste zste xnod ynod znod xmin ymin zmin xmax ymax zmax e 0 e 0 e 0 psize 20 psize 10 psize 10 es 200 HH es 400 es 1 O O 10 4000 4000 10 xbase ybase zbase is the position in meshunit of the first point in the data section below Distance between adjacent grid pts on the x axis 20 nm etc The sign on this value determines the grid orientation relative to xbase ybase zbase Number of nodes along the x axis etc integers Corner points defining mesh bounding box in meshunit Floating point values Fundamental field value unit treated as
243. lute coordinate representations The representation used is selected in the Oxs_Ext object Specify block by the optional script_args entry The Tcl proc itself is specified by the script entry as seen in this example Specify ScriptScalarField Ms atlas atlas script_args rawpt script SatMag proc SatMag x yz f if z lt 20e 9 return 8e5 return 5e5 The value associated with the label script_args should in this case be a subset of relpt rawpt minpt maxpt span scalars vectors as explained in the Oxs_ScriptScalarField documentation page 85 Here rawpt provides the point representation in problem coordi nates i e in meters Other Oxs_Ext objects support a different list of allowed script_args values Check the documentation of the Oxs_Ext object in question for details Please note that the names used in the proc argument lists above are for exposition purposes only You may use other names as you wish It is the order of the arguments that is important not their names Also because the MIF file is parsed first in toto before the Specify blocks are evaluated the support procs may be placed anywhere in the MIF file regardless of the location of the referencing Specify blocks The command call to the Tcl support proc is actually built up by appending to the script value the arguments as specified by the script_args value This allows additional arguments to the Tcl proc to be specified in the script value in which case
244. main walls at surfaces Phys Rev B 43 3395 3422 1991 J Stoer and R Bulirsch Introduction to Numerical Analysis Springer New York 1993 2nd edn E C Stoner and E P Wohlfarth A mechanism of magnetic hysteresis in heterogeneous alloys Phil Trans Royal Soc London A240 599 642 1948 B B Welch Practical Programming in Tcl and Tk Prentice Hall Upper Saddle River New Jersey USA 2000 3rd edn J Xiao A Zangwill and M D Stiles Boltzmann test of Slonczewski s theory of spin transfer torque Phys Rev B 70 172405 pages 4 2004 235 22 Credits The main contributors to this document are Michael J Donahue michael donahue nist gov and Donald G Porter donald porter nist gov both of ITL NIST Section 3 is based on notes from Dianne P O Leary The OOMMF code is being developed mainly by Michael Donahue and Donald Porter Robert D McMichael rmcmichael nist gov made contributions to the early development of the 2D micromagnetic solver Jason Eicke wrote the first version of the problem editor and worked on the self magnetostatic module of the 2D micromagnetic solver Numerous users have contributed to the development of OOMMF by submitting bug re ports small pieces of code or suggestions for improvements Many thanks to all these people including Atif Aziz Loris Bennett Richard Boardman Greg Brown Dieter Buntinx Ngoc Nga Dao Hans Fangohr Colm Faulkner Olivier G rar
245. methods requires 6 evaluations of m if the step is accepted 7 if rejected The difference between the methods involves tradeoffs be tween stability and error minimization The RK5 4 7FS method has the best stability RK5 4 7FM the smallest error and RK5 4 7FC represents a compromise between the two The default method used by Oxs_RungeKuttaEvolve is RK5 4 7FC The remaining undiscussed entry in the Oxs_RungeKuttaEvolve Specify block is en ergy_precision This should be set to an estimate of the expected relative accuracy of the energy calculation After accounting for any change in the total energy arising from time varying applied fields the energy remainder should decrease from one step of the LLG ODE to the next Oxs_RungeKuttaEvolve will reject a step if the energy remainder is found to increase by more than that allowed by eprecision The default value for eprecision is 10 This control may be disabled by setting eprecision to 1 The Oxs_RungeKuttaEvolve module provides the same five scalar outputs and three vector outputs as Oxs_EulerEvolve Examples sample mif acsample mif varalpha mif yoyo mif Oxs_SpinXferEvolve Time evolver that integrates an Landau Lifshitz Gilbert ODE aug mented with a spin momentum term 21 dm dm u y m x He a mx m y Ge m x m x m hfe mx m 4 compare to 3 where m reduced magnetization M M y Gilbert gyromagnetic ratio o JAJ ue tM m unit electron pol
246. mines the ratio of data points to displayed points For example a value of 5 means that every fifth vector on the grid is displayed This means that the number of vectors displayed is 25 times fewer than the number of vectors on the grid For an irregular grid of vectors an average cell size is computed and the Subsample takes values in units of 0 1 times the average cell size A square grid of that size is overlaid on the irregular grid For each cell in the square grid the data vector from the irregular grid closest to the center of the square grid cell is selected for display The vector is displayed at its true location in the irregular grid not at the center of the square grid cell As the subsample rate changes the set of displayed vectors also changes which can in some circumstances substantially change the appearance of the displayed vector field Using mmDisp as a WWW browser helper application You may configure your web browser to automatically launch mmDisp when downloading an OVF file The exact means to do this depends on your browser but a couple of examples are presented below In Netscape Navigator 4 X bring up the Edit Preferences dialog box and select the Category Navigator Applications subwindow Create a New Type with the following fields Description of type OOMMF Vector Field MIME Type application x oommf vf Suffixes ovf omf ohf obf Application tclsh oommfroot oommf tcl fg mmDisp net 0 arg On
247. mmdisp config 146 recognized as OOMMF Vector Field files you must repeat the New Type entry for each file extension In the Application field the values of tclsh oommfroot and arg vary with your platform configuration The value of tclsh is the full path to the telsh application on your platform see Section 5 On Unix systems tclsh may be omitted assuming that the oommf tcl script is executable If tclsh is not omitted on Unix systems Netscape may issue a security warning each time it opens an OOMMEF Vector Field file The value of oommfroot should be the full path to the root directory of your OOMMF installation The value of arg should be 1 on Windows and s on Unix The MIME type application x oommf vf must be configured on any HTTP server which provides OOMMF Vector Field files as well For Microsoft Internet Explorer 3 X bring up the View Options dialog box and select the Program tab Hit the File Types button followed by the New Type button Fill the resulting dialog box with Description of type OOMMF Vector Field Associated extension ovf Content type MIME application x oommf vf You may also disable the Confirm open after download checkbutton if you want Then hit the New button below the Actions window and in the pop up fill in Action open Application used to perform action tclsh oommfroot oommf tcl fg mmDisp net 0 1 Hit OK Close Close and OK Replace tclsh and oommf
248. mplete your report the fewer followup messages will be required to determine the cause of your problem Usually when a problem arises there is an error message produced by the OOMMF software A stack trace may be offered that reveals more detail about the error When reporting an error it will help the developers diagnose the problem if users cut and paste into their problem report the error message and stack trace exactly as reported by OOMMEF software In addition PLEASE include a copy of the output generated by tclsh oommf tcl platform this is important because it will help OOMMF developers identify problems that are installation or platform dependent Before making a report to the OOMMF developers please check the following list of fixes for known problems Additional problems discovered after release will be posted to version specific patch pages at the OOMMF web site 1 When compiling Sec 2 2 3 there is an error about being unable to open system header files like stdlib h time h math h or system libraries and related program startup code This usually indicates a bad compiler installation If you running on Windows and building with the the Microsoft Visual C command line compiler did you remember to run vcvars32 bat to set up the necessary environment variables If you are using the Borland C compiler are the bcc32 cfg and ilink32 cfg files properly configured In all cases check carefully any notes in the chapter Advance
249. mulations the driver must be an Oxs_TimeDriver object and the evolver must be a time evolver such as Oxs_RungeKuttaEvolve The evolver to be used is cited inside the driver Specify block so the evolver must precede the driver in the MIF 2 1 file As noted above the pointwise saturation magnetization Ms and initial magnetization configuration mO are declared inside the driver Specify block as well The pre specified outputs indicated by zero or more Destination and Schedule com mands are conventionally placed after the Specify blocks Output selection can also be 180 modified at runtime using the Oxsii Sec 7 1 page 34 or Boxsi Sec 7 2 page 39 inter active interfaces Auxiliary Tcl procs may be placed anywhere in the file but commonly either near their point of use or else at the bottom of the MIF file If a proc is only referenced from inside Specify blocks then it can be placed anywhere in the file On the other hand if a proc is used at the top level of the MIF file for example to dynamically create part of the problem specification on the fly then it must be defined before it is used in the normal Tcl manner A sample MIF 2 1 file is presented in Fig 7 Sec 17 1 5 pages 198 201 More details on the individual Oxs_Ext objects can be found in the Standard Oxs_Ext Child Classes portion Sec 7 3 page 45 of the Oxs documentation 17 1 2 MIF 2 1 Extension Commands In addition to the standard Tcl commands modulo t
250. n in Oxs_EulerEvolve The effective step_headroom is automatically adjusted by the evolver between the min_headroom and maz_headroom limits to make the observed reject proportion ap proach the reject_goal default value 0 05 The method entry selects a particular Runge Kutta implementation It should be set to one of rk2 rk4 rkf54 rkf54m or rkf54s the default value is rkf54 The rk2 and rk4 methods implement canonical second and fourth global order Runge Kutta methods 18 respectively For rk2 stepsize control is managed by comparing m at the middle and final points of the interval similar to what is done for stepsize control for the Oxs_EulerEvolve class One step of the rk2 method involves 2 evaluations of m In the rk4 method two successive steps are taken at half the nominal step size and 70 the difference between that end point and that obtained with one full size step are compared The error is estimated at 1 15th the maximum difference between these two states One step of the rk4 method involves 11 evaluations of m but the end result is that of the 2 half sized steps The remaining methods rkf54 rkfo4m and rkf54s are closely related Runge Kutta Fehlberg methods derived by Dormand and Prince 7 8 In the nomenclature of these papers rkf54 implements RK5 4 7FC rkf54m implements RK5 4 7FM and rkf54s implements RK5 4 7FS All are 5th global order with an embedded 4th order method for stepsize control Each step of these
251. n state control buttons are three display lines showing the name of the input MIF file the current run state and the current stage number maximum stage number Both stage numbers are 0 indexed Details As with Oxsii the simulation model construction is governed by the Specify blocks in the input MIF file and all aspects of the simulation are determined by the specified Oxs_Ext classes Sec 7 3 Refer to the appropriate Oxs_Ext class documentation for simulation and computational details Threading considerations As an example suppose you are running on a four dual core processor box where each of the four processors is connected to a separate memory node In other words there are eight cores in total and each pair of cores shares a memory node Further assume that the processors are connected via point to point links such as AMD s HyperTransport or Intel s QuickPath Interconnect 43 If you want to run a single instance of Boxsi as quickly as possible you might use the threads 8 option which assuming the default value of numanodes none is in effect would allow the operating system to schedule the eight threads among the system s eight cores as it sees fit Or you might reduce the thread count to reserve one or more cores for other applications If the job is long running however you may find that the operating system tries to run multiple threads on a single core perhaps in order to leave other cores idle so that the
252. nce of Oxsii then Oxsii will likely run fastest if the thread count is set to the number of processing cores on the machine and nodes is set to auto If you want to run multiple copies of Oxsii simultaneously or run Oxsii in parallel with some other application s then set the thread count to a number smaller than the number of processing cores and restrict Oxsii to some subset of the memory nodes with the numanodes option and an explicit nodes list The environment variable OOMMF_NUMANODES may be used to override the default none setting but is subordinate to the command line setting if any miffile Load and solve the problem found in miffile which must be either in the MIF 2 format or convertible to that format by mifconvert Optional 36 All the above switches are optional Since Oxsii does not present any user interface window of its own it depends on mm Launch to provide an interface on its behalf The entry for an instance of Oxsii in the Threads column of any running copy of mmLaunch has a checkbutton next to it This button toggles the presence of a user interface window through which the user may control that instance of Oxsii Inputs Unlike mmSolve2D Sec 10 1 Oxsii loads problem specifications directly from disk via the File Load menu selection rather than through mmProbEd Sec 8 or File Source Sec 9 Input files for Oxsii must be either in the MIF 2 Sec 17 1 format or convertible to that f
253. new application Because of this architecture most OOMMEF applica tions are launched as child processes of an account service directory application These child processes inherit their environment from their parent account service directory application including their working directory and other key environment variables such as DISPLAY Each account service directory application sets its working directory to the root directory of the OOMMF distribution Future releases of OOMMEF software will likely be based on a revised architecture which alleviates these restrictions These service directory applications are vitally important to the operation of the total OOMMF micromagnetic simulation system However it would be easy to overlook them They act entirely behind the scenes without a user interface window Furthermore they are never launched by the user When any server application needs to register its service if it finds that these service directory applications are not running it launches new copies of them In this way the user can be sure that if any OOMMF server applications are running then so are the service directory applications needed to direct clients to its service After all server applications terminate and there are no longer any services registered with a service directory application it terminates as well Similarly when all service directory applications terminate the host service directory application exits In the se
254. nformational and warning messages Optional unsafe Runs embedded Tcl scripts if any in unsafe interpreter Optional v or version Print version string and stop input _file Name of the import micromagnetic problem specification file in MIF 1 1 MIF 1 2 or MIF 2 0 format Use to read from stdin Required co 99 output_file Name of the export micromagnetic problem specification file Use to write to stdout Required 16 12 ODT Column Extraction odtcols The odtcols utility extracts column subsets from ODT Sec 18 data table files Launching The odtcols launch command is tclsh oommf tcl odtcols standard options f format m missing q s S t output_type w colwidth col lt infile gt outfile where 173 f format C printf style format string for each output item Optional The default format string is 4 colwidth s m missing String used on output to designate a missing value Default is the two character open close curly brace pair as specified by the ODT file format Sec 18 q Silences some meaningless error messages such as broken pipe when using the Unix head or tail utilities s Produces a file summary instead of column extraction Output includes table titles column and row counts and the header for each specified column If no columns are specified then the headers for all the columns are listed S Same as s option except the column list is i
255. ng coefficient When multiple copies of mmLaunch are used each can have its own interface to a running copy of mmSolve2D When the interface presented by one copy of mmLaunch is used to set the output schedule in mmSolve2D those settings are not reflected in the interfaces presented by other copies of mmLaunch For example although the first interface sets a schedule that DataTable data is to be sent to an instance of mmGraph every third Iteration there is no indication of that schedule presented to the user in the second interface window It is unusual to have more than one copy of mmLaunch running simultaneously However this bug also appears when one copy of mmLaunch is used to load a problem and start a solver and later a second copy of mmLaunch is used to monitor the status of that running solver A bug in the network traffic handling code of Tcl on Windows 9X systems can sometimes interfere with communications between the control interface of mmSolve2D and the actual computation engine If mmSolve2D is sending out data to two or more data display services every iteration the resulting network traffic can crowd out the receipt of control messages from the control interface You may observe this as a long delay between the time you click the Pause button and the time the solver stops iterating This bug first appeared in Tcl release 8 0 3 and remained through Tcl release 8 1 1 It is fixed in Tcl releases 8 2 and later which we recommend
256. nge in me ters The minpt and maxpt arguments list the minimum and maximum values of the bounding box coordinate by coordinate while span provides the 3 vector resulting from maxpt minpt The relpt selection provides x_rel y_rel z_rel where each element lies in the range 0 1 indicating a relative position between minpt and maxpt coordinate wise Each of the script_args discussed so far places exactly 3 arguments onto the Tcl proc argument list The last two scalars and vectors place arguments depending on the size of the scalar_fields and vector_fields lists The scalar_fields value is a list of other scalar field objects Each scalar field is evaluated at the point in question and the resulting scalar value is placed on the Tcl proc argument list in order The vector fields option works similarly except each vector field generates three points for the Tcl proc argument list since the output from vector field objects is a three vector Although the use of these entries appears complicated this is a quite powerful facility that allows nearly unlimited control for the modification and combination of other field objects Both scalar_fields and vector_fields entries are optional 85 If script_args is not specified the default value relpt is used Note that if script_args includes relpt minpt maxpt or span then a bounding box must be specified as discussed above The following example uses the explicit range method See
257. niformVectorField objects a notational short hand is allowed that lists only the value The previous example is exactly equivalent to Specify Oxs_TimeDriver Ms 8e5 where an implicit Oxs_UniformScalarField object is created with value set to 8e5 Examples sample mif cgtest mif Oxs_AtlasScalarField Declares values that are defined across individual regions of an Oxs Atlas The Specify block looks like Specify Oxs_AtlasScalarField value atlas atlas_spec multiplier mult default_value scalar_field_spec values region1_label scalar_field_spec1 region2_label scalar_field_spec2 The specified atlas is used to map cell locations to regions the value at the cell location of the scalar field from the corresponding values sub block is assigned to that cell The default_value entry is optional if specified and if a cell s region is not included in the values sub block then the default_value scalar field is used If default_value is not specified then missing regions will raise an error 83 The scalar field entries may specify any of the scalar field types described in this Field Objects section As usual one may provide a single numeric value in any of the scalar_field_spec positions this will be interpreted as requesting a uniform spatially homogeneous field with the indicated value If the optional multiplier value is provided then each field value is scaled multiplied by the value mult The vector field
258. node 0 to node 2 may require two hops from node 0 to node 1 and then from node 1 to node 2 In this case numanodes 0 1 will probably run faster than numanodes 0 2 The numanodes option is only available on Linux boxes if the numactl and numactl devel packages are installed The numactl command itself can be used to tie jobs to particular memory nodes similar to the boxsi numanodes option except that numanodes ties threads whereas numact1 ties jobs The numactl hardware command will tell you how many memory nodes are in the system and also reports a measure of the memory latency and bandwidth distance between nodes This information can be used in selecting nodes for the boxsi numanodes option but in practice the distance information reported by numactl is often not reliable For best results one should experiment with different settings or run memory bandwidth tests with different node pairs Known Bugs Boxsi suffers from the same Windows 9X Tcl network traffic bug as Oxsii OOMMF users on Windows 9X systems are encouraged to upgrade to Tcl 8 2 or later 44 7 3 Standard Oxs Ext Child Classes An Oxs simulation is built as a collection of Oxs_Ext Oxs Extension objects These are defined via Specify blocks in the input MIF 2 file Sec 17 1 The reader will find the information and sample MIF file Fig 7 provided in that section to be a helpful adjunct to the material presented below Addition example MIF 2 files
259. nput files having a rectangular grid structure Default value is 1 i e no subsampling infile Name of input file to process Must be one of the recognized formats OVF 0 0 OVF 1 0 or VIO If no file is specified reads from stdin outfile Name of output file If no file is specified writes to stdout The clip option is useful when one needs to do analysis on a small piece of a large simulation The info option is helpful here to discover the extents of the original mesh The flip option can change be used to align different simulations to the same orien tation It can also be used to change a file into its mirror image for example flip x y z reflects the mesh through the yz plane If both clip and flip options are specified then clipping is applied first using the original coordinates The format text and grid irreg options are handy for preparing files for import into non OOMMF applications since all non data lines are readily identified by a leading and each data line is a 6 tuple consisting of the node location and vector value Pay attention however to the scaling of the vector value as specified by valueunit and valuemultiplier header lines For output format details see the OVF file description Sec 19 1 page 220 Known Bugs If the input file contains an explicit boundary polygon cf the boundary entry in the Segment Header block subsection of the OVF file description Sec 19 1
260. nstance of mmArchive and select the Stage check box for the Magnetization output mmArchive destination pair Stages denote points in the simulation where some significant event occurs such as when an equilibrium is reached or some preset simulation time index is met These criteria are set by the input MIF file e Tabular data may be saved by sending scheduled output from the solver to mmArchive which will automatically save all the data it receives Alternatively mmGraph can perform this function Schedule output to mmGraph as desired and use ei ther the interactive or automated save functionality of mmGraph Sec 12 You can setup the solver data scheduling before the calculation is started but must wait for the first data point to configure mmGraph before saving any data As a workaround you may configure mmGraph by sending it the initial solver state interactively and then use the Options clear Data menu item in mmGraph to remove the initializing data point Midcourse control e On the Oxsii window buttons can stop and restart the calculation Reload Reload the same file from disk Reset Return to problem start Run Step through all stages until all complete Relax Run until the current stage termination criteria are met Step Do one solver iteration and then pause Pause Click anytime to stop the solver Continue simulation from paused point with Run Relax or Step Stage Interactively change t
261. number of attempts required to bracket energy minimum during first phase of line minimization procedures e Line min count total number of minimization steps during second phase of line minimization procedures i e steps after minimum has been bracketed 76 e Cycle count number of line direction selections e Cycle sub count number of line direction selections since the last gradient direction reset The vector field outputs are e H total effective field in A m e mxHxm in A m m is the unit magnetization direction Examples cgtest mif stdprob3 mif yoyo mif 7 3 5 Drivers While evolvers Sec 7 3 4 are responsible for moving the simulation forward in individual steps drivers coordinate the action of the evolver on the simulation as a whole by grouping steps into tasks stages and runs Tasks are small groups of steps that can be completed without adversely affecting user interface responsiveness Stages are larger units specified by the MIF problem description in particular problem parameters are not expected to change in a discontinuous manner inside a stage The run is the complete sequence of stages from problem start to finish The driver detects when stages and runs are finished using criteria specified in the MIF problem description and can enforce constraints such as making sure stage boundaries respect time stopping criteria There are two drivers in Oxs Oxs_TimeDriver for controlling time evolvers such
262. o machines This script should be run with the command tclsh oommf tcl batchmaster multitask tcl bar where bar is the name of the local machine Near the top of the multitask tcl script several Tcl variables RMT_MACHINE through A_list are defined these are used farther down in the script The remote machine is speci fied as foo which is used in the TaskInfo AppendSlave and TaskInfo ModifyHostList commands There are two AppendSlave commands one to run two slaves on the local machine and one to run a single slave on the remote machine foo The latter changes to a specified working directory before launching the batchslave application on the remote machine For this to work you must have rsh configured properly In the future it may be possible to launch remote commands using the OOMMEF account server application thereby lessening the reliance on system commands like rsh Below this the slave initialization script is defined The Tcl regsub command is used to place the task script defined value of BASEMIF into the init script template The init script is run on the slave when the slave is first brought up It first reads the base MIF file into a newly created mms mif instance The MIF file needs to be accessible by the slave process irrespective of which machine it is running on Then replacement SolverTaskInit and SolverTaskCleanup procs are defined The new SolverTaskInit interprets its first argument as a value for the exchange cons
263. o ppm instead filter program Post processing application to run on each avf2ppm output file May be a pipeline of several programs format lt P3 P6 B24 gt Specify the output image file format Currently supported for mats are the true color Portable Pirmap PPM formats P3 ASCII text and P6 binary and the uncompressed Windows BMP 24 bits per pixel format The default is P6 ipat pattern Specify input files using a pattern with glob style wildcards Mostly useful in DOS opatexp regexp Specify the regular expression applied to input filenames to determine portion to be replaced in generation of output filenames The default regular expression is 7 707 707 7 1 opatsub sub The string with which to replace the portion of input filenames matched by the opatexp regexp during output filename generation The default is ppm for type P3 and P6 file output bmp for B24 file output v level Verbosity informational message level with 0 generating only error messages and larger numbers generating additional information The level value is an integer defaulting to 1 infile List of input files to process The file specification options require some explanation Input files may be specified either by an explicit list infile or by giving a wildcard pattern e g ipat omf which is expanded in the usual way by avf2ppm using the Tcl command glob Unix shells sh csh etc automatically e
264. ocalhost port is the port address for the master default is 0 which selects an arbitrary open port When batchmaster is run it sources the task script Tcl commands in the task script should modify the global object TaskInfo to inform the master what tasks to perform and optionally how to launch slaves to perform those tasks The easiest way to create a task script is to modify one of the example scripts in Sec 10 2 2 4 More detailed instructions are in Sec 10 2 2 3 After sourcing the task script batchmaster launches all the specified slaves initializes each with a slave initialization script and then feeds tasks sequentially from the task list to the slaves When a slave completes a task it reports back to the master and is given the next unclaimed task If there are no more tasks the slave is shut down When all the tasks are complete the master prints a summary of the tasks and exits When the task script requests the launching and controlling of jobs off the local machine with slaves running on remote machines then the command line argument host must be set to the local machine s network name and the TaskInfo methods AppendSlave and ModifyHostList will need to be called from inside the task script Furthermore OOMMF does not currently supply any methods for launching jobs on remote machines so a task script which requests the launching of jobs on remote machines requires a working rsh command or equivalent See Sec 10 2 2 3
265. of mmSolve2D Launching mmSolve2D may be started either by selecting the mmSolve2D button on mmLaunch or from the command line via tclsh oommf tcl mmSolve2D standard options restart lt 0 1 gt restart lt 0 1 gt Affects the behavior of the solver when a new problem is loaded Default value is 0 When launched with restart 1 the solver will look for basename log and basename omf files to restart a previous run from the last saved state where basename is the Base Output Filename specified in the input MIF 1 1 problem specification file Sec 17 3 If these files cannot be found then a warning is issued and the solver falls back to the default behavior restart 0 of starting the problem from scratch The specified restart setting holds for all problems fed to the solver not just the first There is currently no interactive way to change the value of this switch Since mmSolve2D does not present any user interface window of its own it depends on mmLaunch to provide an interface on its behalf The entry for an instance of mmSolve2D in the Threads column of any running copy of mmLaunch has a checkbutton next to it This button toggles the presence of a user interface window through which the user may control that instance of mmSolve2D The user interface window is divided into panels providing user interfaces to the Inputs Outputs and Controls of mmSolve2D Inputs The top panel of the user interface window may be o
266. of the image respectively to axes in the simulation The image is scaled as necessary along each dimension to match the atlas extents along the corresponding axes The image is overlaid through the entire depth of the perpendicular dimension i e along the axis absent from the viewplane specification The Oxs_ImageAtlas class can be used inside a Oxs_MultiAtlas object to specify regions in a multilayer structure The image entry specifies the name of the image file to use If the file path is relative then it will be taken with respect to the directory containing the MIF file The image format may be any of those recognized by any2ppm Sec 16 1 The file will be read directly by Oxs if it is in the P3 or P6 PPM formats otherwise any2ppm will be automatically launched to perform the conversion The colormap value is an even length list of color region name pairs The colors may be specified in any of several ways The most explicit is to use one of the Tk numeric formats rgb rrggbb rrrgggbbb or rrrrggggbbbb where each r g and b is one hex digit i e 0 9 or A F representing the red green and blue components of the color respectively For example F00 is bright full scale red 800 would be a darker red while FF0 and FFFFOO would both be bright yellow Refer to the Tk_GetColor documentation for details For shades of gray the special notation grayD or greyD is available where D is a decimal value between 0 and 100 e g grey0
267. olor_distance is 3 which means all colors match The following example should help clarify these matters 48 Specify Oxs_ImageAtlas atlas xrange 0 400e 9 yrange 0 200e 9 zrange 0 20e 9 image mypic gif viewplane xy colormap blue cobalt red permalloy green universe default cobalt matcherror 1 Blue pixels get mapped to the cobalt region and red pixels to the permalloy region Green pixels are mapped to the universe non region which means they are considered to be outside the atlas entirely This is a fine point but comes into play when atlases with overlapping bounding boxes are brought together inside an Oxs_MultiAtlas To which region would an orange pixel be assigned The scaled triplet representation for orange is 1 0 647 0 so the distance to blue is 1 191 the distance to red is 0 647 and the distance to green is 1 06 Thus the closest color is red but 0 647 is outside the matcherror setting of 0 1 so orange doesn t match any of the colors and is hence assigned to the default region which in this case is cobalt On the other hand if matcherror had been set to say 1 then orange and red would match and orange would be assigned to the permalloy region Pixels with colors that are equidistant to and match more than one color in the col ormap will be assigned to one of the closest color regions The user should not rely on any particular selection that is to say the explicit mat
268. olve tcl proc redefinitions set init_script Initialize solver This is run at global scope set basename __BASEMIF__ Base mif filename global mms_mif New mif mif Read FindFile basename mif Redefine TaskInit and TaskCleanup proc s proc SolverTaskInit args global mif outtextfile basename set A lindex args 0 set outbasename basename A A mif SetA A mif SetOutBaseName outbasename set outtextfile open outbasename odt a 124 puts outtextfile GetTextData header Run on basename mif with A mif GetA flush outtextfile proc SolverTaskCleanup args global outtextfile close outtextfile Substitute BASEMIF in for __BASEMIF__ in above script regsub all __BASEMIF__ init_script BASEMIF init_script TaskInfo SetSlaveInitScript init_script Create task list foreach A A_list TaskInfo AppendTask A A BatchTaskRun A Figure 3 Advanced sample task script multitask tcl 125 11 Data Table Display mmDataTable W Iteration E Field Updates E Sim Time File Data Options M Time Step E Step Size Bx Iteration 873 Field Updates 1891 Sim Time ns 9 52874 M By Step Size 0 965 Bz Im x h 0 005406 TB By mT 4 mmx hl Total Energy J m 3 9352 84 I Mx Ms Exchange Energy J m 3 328 02 My Ms Anisotropy Energy J m 3 119 53 M MziMs Demag Energy J m 3 3051 23 E Total Energy Zeeman Energy J m 3 5854 06 W Exchange Energ
269. om the script are size adjusted to the specified magnitude If both norm 93 and multiplier are specified then the field vectors are first normalized before being scaled by the multiplier value The following example produces a vortex like unit vector field with an interior core region pointing parallel to the z axis Here the scaling region is specified using an atlas reference to an object named atlas which is presumed to be defined earlier in the MIF file See the Oxs_ScriptScalarField sample Specify block for an example using the explicit range option proc Vortex xrel yrel zrel set xrad expr xrel 0 5 set yrad expr yrel 0 5 set normsq expr xrad xrad yrad yrad if normsq lt 0 025 return 0 0 1 return list expr 1 yrad xrad 0 Specify Oxs_ScriptVectorField script Vortex norm 1 atlas atlas See also the Oxs MaskVectorField documentation and the discussion of the ReadFile MIF extension command in Sec 17 1 2 for other example uses of the Oxs_ScriptVectorField class Examples cgtest mif ellipsoid mif manyregions scriptfields mif sample vecreflect 1 stdprob3 mif yoyo mif Oxs_FileVectorField Provides a file specified vector field The Specify block has the form Specify Oxs FileVectorField name file filename atlas atlas_spec xrange rmin zmar yrange ymin ymar zrange zmin zmar spatial_scaling zscale yscale zscale spatial_offset zoff yoff zoff exteri
270. omf opatsub gif filter ppmtogif On Unix either drop the ipat flag or use quotes to protect the input file specification string from expansion by the shell as in ipat omf You may also pipe together multiple filters e g filter ppmquant 256 ppmtogif Configuration files The details of the conversion process are specified by plain text configuration files in the same format as the mmDisp configuration file Sec 13 page 142 Each of the configurable parameters is an element in an array named plot_config The default values for this array are read first from the main configuration file oommf app mmdisp scripts avf2ppm config followed by the local customization file oommf app mmdisp scripts local avf2ppm config if it exists Lastly any files passed as config options on the command line are input Each of these parameters is interpreted as explained in the mmDisp documentation q v except that avf2ppm ignores the misc defaultwindowwidth and misc defaultwindowheight pa rameters and the following additional parameters are available arrow antialias If 1 then each pixel along the edge of an arrow is drawn not with the color of the arrow but with a mixture of the arrow color and the background color This makes arrow boundaries appear less jagged but increases computation time Also the colors used in the anti aliased pixels are not drawn from the arrow or pixel colormap discretizations so color allocation in
271. on OID nomenclature used in the graphical interface because in general it is not possible to know the OOMMEF ID for application instances at the time the MIF file is composed In fact some of the applications may be launched by Destination commands and so don t even have OID s at the time the Destination command is processed 186 The event parameter should be one of the keywords Step or Stage and the frequency parameter should be a positive integer representing with what frequency of the spec ified event should output be dispatched For example if Step 5 is given then on every fifth step of the solver output of the indicated type will be sent to the selected destination Set frequency to 1 to send output each time the event occurs All of the parameters to the Schedule command are required There are examples of scheduling with the Destination and Schedule commands in the sample MIF 2 1 file presented in Fig 7 Sec 17 1 5 pages 198 201 There three destinations are tagged The first refers to a possibly already running instance of mmGraph having nickname Hysteresis The associated Schedule command sends DataTable output to this application at the end of each Stage so hysteresis graphs can be produced The second destination tag references a different copy of mmGraph that will be used for monitoring the run To make sure that this output is rendered onto a blank slate the new keyword is used to launch a fresh copy of mmGraph The
272. on we refer to this program as wish Consult your Tcl Tk documentation to determine the actual names of these programs on your platform for example tclsh83 exe or wish8 0 OOMMF applications communicate via TCP IP network sockets This means that OOMMF requires support for networking even on a stand alone machine At a minimum OOMMF must be able to access the loopback interface so that the host can talk to itself using TCP IP OOMMEF applications that use Tk require a windowing system and a valid display On Unix systems this means that an X server must be running If you need to run OOMMF applications on a Unix system without display hardware or software you may need to start the application with command line option tk 0 see Sec 5 or use the Xvfb virtual frame buffer The OOMMF source distribution unpacks into a directory tree containing about 800 files and directories occupying approximately 10 MB of storage The amount of disk space needed for compiling and linking varies greatly between platforms allow an additional 15 MB to 80 MB for the build Removing intermediate object modules cf the pimake objclean target in Reducing Disk Space Usage Sec 2 3 1 below reduces the final space requirement for source binary executables to between 15 MB and 25 MB The OOMMF distribution containing Windows executables unpacks into a directory tree occupying about 15 MB of storage Note On a non compressed FAT16 file system on a large di
273. ons may be shortened misc crop If disabled 0 then any leftover space in the bitmap of dimensions misc width by misc height after packing the image are filled with the background color If en abled 1 then the bitmap is cropped to just include the image with the margin specified by misc margin NOTE Some movie formats require that bitmap dimen sions be multiples of 8 or 16 For such purposes you should disable misc crop and specify appropriate dimensions directly with misc width and misc height 166 The default configuration file shown in Fig 6 page 168 can be used as a starting point for user configuration files You may also use configuration files produced by the File Write config command in mm Disp although any of the above avf2ps specific parameters that you wish to use will have to be added manually using a plain text editor You may omit any entries that you do not want to change from the default You may layer configuration files by specifying multiple user configuration files on the command line These are processed from left to right with the last value set for each entry taking precedence 16 6 Vector Field File Difference avfdiff The avfdiff program computes differences between vector field files in any of the recognized formats OVF VIO see Sec 19 The input data must lie on rectangular meshes with identical dimensions Launching The avfdiff launch command is tclsh oommf tcl avfdiff standard
274. options info file O file 1 file n where info Prints statistics on file differences If this option is selected then no output files are created file O Name of input file to subtract from other files Must be either an OVF 1 0 file in the rectangular mesh subformat or an VIO file Required file 1 Name of first input file from which file O is to be subtracted Must also be either an OVF 1 0 file in the rectangular mesh subformat or an VIO file and must have the same dimensions as file O Required file n Optional additional files from which file O is to be subtracted with the same requirements as file 1 For each input file file 1 through file n a separate output file is generated in the OVF 1 0 format Each output file has a name based on the name of corresponding input file with a diff suffix If a file with the same name already exists it will be overwritten For output file format details see the OVF file description Sec 19 1 16 7 Cyclic Redundancy Check crc32 The cre32 application computes 32 bit cyclic redundancy checksums CRC 32 on files 167 array set plot_config arrow status 1 arrow colormap Black Gray White arrow colorcount arrow quantity arrow colorinvert 0 Zz arrow colorphase 0 0 1 arrow autosample arrow subsample 10 arrow size 1 arrow antialias 1 pixel status 1 pixel colormap Teal White Red pixel colorcount 225 pixel opaque pixel quantity pixel colorph
275. or arrow size and colormap ranges equivalent to the Data Scale control In general this should be a positive real value but a zero or empty value will set the scaling to its default setting misc centerpt If specified the value should be a three item list of real numbers specifying the center of the display x y z in file mesh units e g meters misc relcenterpt If specified the value should be a three item list of real numbers in the range 0 1 specifying the center of the display in relative coordinates If both misc relcenterpt and misc centerpt are defined then misc centerpt takes prece dence viewaxis Select the view axis which should be one of z z y y x or x This option is equivalent to the View Viewpoint menu control viewaxis xarrowspan viewaxis yarrowspan viewaxis zarrowspan Specifies the thick ness of the arrow display slice for the corresponding view For example if the view axis is z or z then only viewaxis zarrowspan is active The value for each element should be either a real value or an empty string If the value is zero or an empty string then the thickness is set to the default value which is typically the thickness of a single cell If the value is positive then it specifies the slice range in file mesh units e g in meters Lastly if the value is negative then the slice is set to the entire thickness of the mesh in that view direction viewaxis xpixelspan viewaxis ypixelspan viewax
276. or ext_flag norm magnitude multiplier mult 94 Required values in the Specify block are the name of the input vector field file and the desired scaling parameters The filename is specified via the file entry which names a file containing a vector field in one of the formats recognized by avf2ovf Sec 16 3 If atlas or xrange yrange zrange are specified then the file will be scaled and translated as necessary to fit that scaling region in the same manner as done for example by the Oxs_ScriptScalarField and Oxs_ScriptVectorField classes Alternatively one may specify spatial_scaling and spatial_offset directly In this case the vector spatial positions are taken as specified in the file multiplied component wise by xscale yscale zscale and then translated by xoff yoff zoff If you want to use the spatial coordinates as directly specified in the file use 1 1 1 for spatial_scaling and 0 0 0 for spatial_offset In all cases once the input field has been scaled and translated it is then sub sampled zeroth order fit as necessary to match the simulation mesh The exterior flag determines the behavior at exterior points i e locations if any in the simulation mesh that lie outside the extent of the scaled and translated vector field The ext_flag should be either a three vector or one of the keywords boundary or error If a three vector is given then that value is supplied at all exterior points If ext_flag is set to bo
277. ormat by the command line tool mifconvert Sec 16 11 There are sample MIF 2 files in the directory oommf app oxs examples MIF files may be edited with any plain text editor Outputs Once a problem has been loaded the scroll box under the Output heading will fill with a list of available outputs The contents of this list will depend upon the Oxs_Ext objects specified in the input MIF file Refer to the documentation for those objects for specific details Sec 7 3 To send output from Oxsii to another OOMMF application highlight the desired selection under the Output heading make the corresponding selection under the Destination heading and then specify the output timing under the Schedule heading Outputs may be scheduled by the step or stage and may be sent out interactively by pressing the Send button The initial output configuration is set by Destination and Schedule commands in the input MIF file Sec 17 1 2 Outputs fall under two general categories scalar single valued outputs and vector field outputs The scalar outputs are grouped together as the DataTable entry in the Output scroll box Scalar outputs include such items as total and component energies average magnetiza tion stage and iteration counts max torque values When the DataTable entry is selected the Destination box will list all OOMMF applications accepting datatable style input i e all currently running mmDataTable Sec 11 mmGraph Sec 12 and mmArchive
278. ositioned over a drawn item in the graph holding down the Control key and the left mouse button will bring up the coordinates of that point with respect to the yl axis Similarly depressing the Control key and the right mouse button or alternatively holding down the Control Shift keys while pressing the left mouse button will bring up the coordinates of the point with respect to the y2 axis The coordinates displayed are the coordinates of a point on a drawn line which are not necessarily the coordinates of a plotted data point The data points are plotted at the endpoints of each line segment The coordinate display is cleared when the mouse button is released while the Control key is down One vertical and one horizontal rule line are also available Initially these rules are tucked and hidden against the left and bottom graph axes respectively Either may be repositioned by dragging with the left or right mouse button The coordinates of the cursor are displayed while dragging the rules The displayed y coordinate corresponds to the yl axis if the left mouse button is used or the y2 axis if the right mouse button or the Shift key with the left mouse button are engaged The graph extents may be changed by selecting a zoom box with the mouse This is useful for examining a small portion of the graph in more detail This feature is activated by clicking and dragging the left or right mouse button A rectangle will be displayed that chang
279. oting re gion in the vector field file over which data is to be collected The locations are in problem units typically meters A single hyphen may be specified for any of the box corner coordinates in which case the corresponding extremal value from the input file is used Optional the default region selects the entire input file rregion rxmin rymin rzmin rxmax rymax rzmax This option is the same as region except that the locations are specified in relative units between 0 and 1 truncate lt 0 1 gt When opening an existing file for output the new output can either be appended to the file truncate 0 or else the existing data can be discarded truncate 1 The default is truncate 0 v level Verbosity informational message level with 0 generating only error messages and larger numbers generating additional information The level value is an integer defaulting to 1 valfunc label units fenexpr Similar to the index option valfunc adds an additional column to the output with label and units as the column header and fcnexpr is a Tcl expr expression that may include special variables Here however the allowed special variables are x y z r vx vy vz vmag where x y z and r are sample location and magnitude respectively r x y 27 and vx vy vz and vmag are vector component values and magnitude The output is the value of fenexpr averaged across the manifold select
280. ound an error is reported 29 The rest of the command line arguments that are not recognized by the bootstrap are passed along as arguments to the application the bootstrap launches Since the bootstrap recognizes command line arguments that begin with and most other applications recognize command line arguments that begin with confusion about which options are provided to which programs can be avoided For example tclsh oommf tcl help mmGraph prints out help information about the bootstrap and exits without launching mmGraph However tclsh oommf tcl mmGraph help launches mmGraph with the command line argument help mmGraph then displays its own help message Most OOMMF applications accept the standard options listed below Some of the OOMMEF applications accept additional arguments when launched from the command line as documented in the corresponding sections of this manual The help command line option can also be used to view the complete list of available options When an option argument is specified as lt 0 1 gt 0 typically means off no or disable and 1 means on yes or enable version Display the version of the application and exit help Display a help message and exit tk lt 0 1 gt Disable or enable Tk Tk must be enabled for an application to display graphi cal widgets However when Tk is enabled on Unix platforms the application is depen dent on an X Windows server If the X Windows server dies it wi
281. ource may then be used to supply the MIF problem description contained in a file to a solver without danger of corrupting its contents Launching FileSource must be launched from the command line You may specify on the command line the MIF problem description file it should serve to client applications The command line is tclsh oommf tcl FileSource standard options filename Although FileSource does not appear on the list of Programs that mmLaunch offers to launch running copies do appear on the list of Threads since they do provide a service registered with the account service directory Inputs FileSource takes its MIF problem description from the file named on the command line or from a file selected through the File Open dialog box No checking of the file contents against the MIF specification is performed The file contents are passed uncritically to any client application requesting a problem description Those client applications should raise errors when presented with invalid problem descriptions Outputs Each instance of FileSource provides the contents of exactly one file at a time The file name is displayed in the FileSource window to help the user associate each instance of 105 FileSource with the data file it provides Each instance of FileSource accepts and services requests from client applications typically solvers for the contents of the file it exports The contents of the file are read at the time of the
282. ov rdm email list html The OOMMF developers are always interested in your comments about OOMMF See the Credits Sec 22 for instructions on how to contact them and for information on referencing OOMMF 2 Installation 2 1 Requirements OOMME software is written in C and Tcl It uses the Tcl based Tk Windowing Toolkit to create graphical user interfaces that are portable to many varieties of Unix as well as Microsoft Windows Tcl and Tk must be installed before installing OOMMF Tcl and Tk are available for free from the Tcl Developer Xchange We recommend the latest stable versions of Tcl and Tk concurrent with this release of OOMMF OOMMF requires at least Tcl version 7 5 and Tk version 4 1 on Unix platforms and requires at least Tcl version 8 0 and Tk version 8 0 on Microsoft Windows platforms OOMMEF software does not support any alpha or beta versions of Tcl Tk and each release of OOMMF may not work with later releases of Tcl Tk Check the release dates of both OOMMF and Tcl Tk to ensure compatibility A Tcl Tk installation includes two shell programs The names of these programs may vary depending on the Tcl Tk version and the type of platform The first shell program contains an interpreter for the base Tcl language In the OOMMF documentation we refer to this program as tclsh The second shell program contains an interpreter for the base Tcl language extended by the Tcl commands supplied by the Tk toolkit In the OOMMF documentati
283. ower to re install an existing broken Tcl Tk installation perhaps you are not the sysadmin of your machine you might still install your own copy of Tcl Tk in your own user space In that case if your private Tcl Tk installation makes use of shared libraries take care that you do whatever is necessary on your platform to be sure that your private tclsh and wish find and use your private shared libraries instead of those from the system Tcl Tk installation This might involve setting an environment variable such as LD_LIBRARY_PATH If you use a private Tcl Tk installation you also want to be sure that there are no environment variables like TCL_LIBRARY or TK LIBRARY that still refer to the system Tcl Tk installation Additional Configuration Issues on Windows A few other configurations should be checked on Windows platforms First note that absolute filenames on Windows makes use of the backslash to separate directory names On Unix and within Tcl the forward slash is used to separate directory names in an absolute filename In this manual we usually use the Tcl convention of forward slash as separator In portions of the manual pertaining only to MS Windows we use the backslash as separator There may be instructions in this manual which do not work exactly as written on Windows platforms You may need to replace forward slashes with backward slashes in pathnames when working on Windows OOMMEF software needs networking support that recogni
284. p flipstr Provides an axis coordinate transformation Flipstr has the form A B C where A B C is a permutation of x y z with an optional minus sign on each entry The first component A denotes the axis to which x is mapped B where y is mapped and C where z is mapped The default is the identity map x y z To rotate 90 about the z axis use flip y x z which sends x to the y axis y to the x axis and leaves z unchanged format lt text b4 b8 gt Specify output data format The default is ASCII text b4 se lects 4 byte binary b8 selects 8 byte binary The OVF format has an ASCII text header in all cases grid lt rectlirreg gt Specify output grid structure The default is rect which will output a regular rectangular grid if the input is recognized as a regular rectangular grid The option grid irreg forces irregular mesh style output info Instead of converting the file print information about the file such as size range and descriptive text from the file header keepbb If the clip option is used then normally the spatial extent i e the boundary of the output is clipped to the specified clip box If keepbb keep bounding box is given then the spatial extent of the output file is taken directly from the input file Clipping is still applied to the data vectors keepbb affects only the action of the clip box on the boundary mag Write out a scalar valued field instead of a vector value field where
285. pened and closed by toggling the Inputs checkbutton When open the Inputs panel reveals two subpanels The left subpanel contains a list of the inputs required by mmSolve2D There is only one item in the list ProblemDescription When ProblemDescription is selected the right subpanel labeled Source Threads displays a list of applications that can supply a problem description The user selects from among the listed applications the one from which mmSolve2D should request a problem description 108 Outputs When mmSolve2D has outputs available to be controlled a Scheduled Outputs check button appears in the user interface window Toggling the Scheduled Outputs checkbutton causes a bottom panel to open and close in the user interface window When open the Scheduled Outputs panel contains three subpanels The Outputs subpanel is filled with a list of the types of output mmSolve2D can generate while solving the loaded problem The three elements in this list are TotalField for the output of a vector field representing the total effective field Magnetization for the output of a vector field representing the current magnetization state of the grid of spins and DataTable for the output of a table of data values describing other quantities of interest calculated by mmSolve2D Upon selecting one of the output types from the Outputs subpanel a list of applications appears in the Destination Threads subpanel which provide a display and or storage ser
286. pr 1 cos phideg pi 180 proc Texture global pi phirange set theta expr 2 rand 1 pi set costheta expr cos theta set sintheta expr sin theta set cosphi expr 1 phirange rand set sinphi expr 1 0 cosphix cosphi 206 if sinphi gt O 0 set sinphi expr sqrt sinphi set x expr sinphi costheta set y expr sinphix sintheta set z expr cosphi return list x y z Set a random unit vector for each grain region set axes for set i 0 i lt grain_count incr i lappend axes i lappend axes Texture Sets the rogue grain Rogue lt grain_count if llength RoguePt 3 The Regions field maps region name which is a number to the corresponding number set regionmap for set i 0 i lt grain_count incr i lappend regionmap i i Specify Oxs_AtlasScalarField Regions subst atlas world values list regionmap foreach x y z RoguePt break set Rogue EvalScalarField Regions x y z set item_number expr 2 Rogue 1 set axes lreplace axes item_number item_number 1 0 O Specify Oxs_AtlasVectorField axes subst atlas world norm 1 0 values list axes Specify Oxs_UniaxialAnisotropy subst K1 Ku axis axes 207 HHHRHHHHHRHHHHHHHHHHHHHHHHHHHHHHH Exchange set A_list for set i 0 i lt grain_count incr i lappend A_list i i A Specify Oxs_Exchange6Ngbr subst
287. quantity 137 142 communication protocol 119 compilers 4 compressed files 130 135 237 configuration values 6 oommf_threads 7 path_directory_temporary 8 thread_count 7 contact information 236 contributors 236 control points see simulation control point CRC 32 167 crystalline anisotropy 210 curve break 130 customize 10 file format translation 135 136 help file browser 151 host server port 27 cut and paste 127 Cygwin see platform Windows Cygwin envi ronment data print 130 136 140 144 save 23 24 130 133 136 140 149 scale 138 slice selection 138 140 zoom 138 decompress see compressed files demagnetization 211 Destination command MIF 149 182 download 4 e mail 2 236 edge anisotropy 210 energy anisotropy 110 112 crystalline anisotropy 210 demag 110 112 236 edge anisotropy 210 exchange 110 112 total 110 112 115 Zeeman 110 112 environment variables DISPLAY 28 inherited from parent process 28 LD_LIBRARY_PATH 8 OOMMF_NUMANODES 13 36 42 OOMMF_TCL_CONFIG 7 OOMMF_TCLSH 7 OOMMF_TEMP 8 OOMMF_THREADS 7 12 36 41 OOMMF_TK_CONFIG 7 OOMMF_WISH 7 OSTYPE 16 PATH 8 TCL_LIBRARY 8 19 TERM 16 TK_LIBRARY 8 EvalScalarField command MIF 203 EvalVectorField command MIF 204 exchange stiffness 210 FFT 112 211 field applied 1 110 115 116 214 demag 1 effective 112 update count 109 field range 213 file bitmap 34 46 49 107 115 1
288. r then there are multiple files in the directory config names that return 1 when run on your computer For each compatible platform name reported edit the corresponding file in config names so that only one of them returns 1 Experimenting using tclsh to probe the Tcl variable tcl_platform should assist you in this task If that fails you can explicitly assign a platform type corresponding to your computing platform by matching its hostname For example if your machine s host name is foo bar net Oc_Config New _ string tolower file rootname file tail info script f if string match foo bar net info hostname return 1 Continue with other tests 14 Contact the OOMMEF developers if you need further assistance 2 4 Platform Specific Installation Issues The installation procedure discussed in the previous sections applies to all platforms Unix Windows Mac OS X There are however some details which pertain only to a particular platform These issues are discussed below 2 4 1 Unix Configuration Missing Tcl Tk files The basic installation procedure should be sufficient to install OOMMF on most Unix systems Sometimes however the build will fail due to missing Tcl header files tcl h tk h or libraries e g libtcl so libtk so This problem can usually be solved by installing a development version of Tcl Tk which may be found on the operating system installation disks or may be available from
289. r The pro grams communicate over Internet TCP IP connections even when the programs are run ning on a common host An advantage of this design is that distributed operation of OOMMF programs over a networked collection of hosts is supported in the basic design and will be available in a future release When two OOMMF applications are in the relationship that one is requesting a service from the other it is convenient to introduce some clarifying terminology Let us refer to the application that is providing a service as the server application and the application requesting the service as the client application Note that a single application can be both a server application in one service relationship and a client application in another service relationship Each server application provides its services on a particular Internet port and needs to inform potential client applications how to obtain its service Each client application needs to be able to look up possible providers of the service it needs The intermediary which brings server applications and client applications together is another application called the account service directory There may be at most one account service directory application running under the user ID of each user account on a host Each account service directory keeps track of all the services provided by OOMMF server applications running under its user account on its host and the corresponding Inte
290. r references to the SVF format A sample OVF 0 0 file is shown in Fig 13 Any line beginning with a character is a comment all others are data lines Each data line is a whitespace separated list of 6 elements the x y and z components of a node position followed by the x y and z components of the field at that position Input continues until the end of the file is reached It is recommended but not required that the first line of an OVF file be OOMMF irregular mesh v0 0 This will aid automatic file type detection Also three special extended comments in OVF 0 0 files are recognized by mmDisp File lt filename or extended filename gt Boundary XY lt boundary vertex pairs gt Grid step lt cell dimension triple gt All these lines are optional The File provides a preferred possibly extended filename to use for display identification The Boundary XY line specifies the ordered vertices of a bounding polygon in the ry plane If given mmDisp will draw a frame using those points to ostensibly indicate the edges of the simulation body Lastly the Grid step line provides three values representing the average x y and z dimensions of the volume corresponding to an individual node field sample It is used by mmDisp to help scale the display Note that the data section of an OVF 0 0 file takes the simple form of columns of ASCII formatted numbers Columns of whitespace separated numbers expressed
291. ral it is possible to have multiple instances of an Oxs_Ext child class in a simulation but each instance must have a unique name These names are used for identification by output routines and to allow one Specify block to refer to another Specify block appearing earlier in the MIF file If the second part of the name 181 is not given then as a default the empty string is appended For example if instead of Oxs_EulerEvolve foo above the name was specified as just Oxs_EulerEvolve then the effective full name of the created object would be Oxs_EulerEvolve The second argument to the Specify command here everything between the curly braces is a string that is interpreted by the new Oxs_Ext child object in its construc tor The format of this string is up to the designer of the child class but there are a number of conventions that designers are encouraged to follow These conventions are described in Specify Conventions Sec 17 1 3 below ClearSpec This command is used to disable one or all preceding Specify commands In particular one could use ClearSpec to nullify a Specify block from a base MIF file that was imported using the ReadFile command Sample usage is ClearSpec Oxs_EulerEvolve foo where the parameter is the full name here Oxs_EulerEvolve foo of the Specify block to remove If no parameter is given then all preceding Specify blocks are removed Destination The format for the Destination command i
292. re discussed below Controls The menu selection File Clear clears the display window The menu selection File Exit terminates the mmDisp application The menu Help provides the usual help facilities The View menu provides high level control over how the vector field is placed in the display window The menu selection View Wrap Display resizes the display window so that it just contains the entire vector field surrounded by a margin View Fill Display resizes the vector field until it fills the current size of the display window If the aspect ratio of the display window does not match the aspect ratio of the vector field a larger than requested margin appears along one edge to make up the difference View Center Display translates the vector field to put the center of view at the center of the display window View Rotate ccw and View Rotate cw rotate the display one quarter turn counter clockwise and clockwise respectively If the display size is not locked see Options Lock size below then the display window also rotates so that the portion of the vector field seen and any margins are preserved unless the display of the control bar forces the display window to be wider View reDraw 136 allows the user to invoke a redrawing of the display window The View Viewpoint tearable submenu supports rotation of the vector field out of the plane of the display so that it may be viewed from along a different axis The menu selection Options Conf
293. rnet ports at which those services may be obtained OOMMF server applications register their services with the corresponding account service directory application OOMMF client applications look up service providers running under a particular user ID in the corresponding account server directory application The account service directory applications simplify the problem of matching servers and clients but they do not completely solve it OOMMEF applications still need a mechanism to find out how to obtain the service of the account service directory Another application called the host service directory serves this function Only one copy of the host service directory application runs on each host Its sole purpose is to tell OOMMF applications where to obtain the services of account service directories on that host Because only one copy of this application runs per host it can provide its service on a well known port which is configured into the OOMMF software By default this is port 15136 OOMMF software can be customized Sec 2 3 2 to use a different port number The account service directory applications perform another task as well They launch other programs under the user ID for which they manage service registration The user controls the launching of programs through the interface provided by the application mm 27 Launch See Sec 6 but it is the account service directory application that actually spawns a subprocess for the
294. roject was first released in October 1998 It included a problem editor a 2D micromagnetic solver and several display widgets including an updated version of mmDisp The solver can be controlled by an interactive interface Sec 10 1 or through a sophisticated batch control system Sec 10 2 This solver was originally based on a micromagnetic code that Mike Donahue and Bob McMichael had previously developed It utilizes a Landau Lifshitz ODE solver to relax 3D spins on a 2D mesh of square cells using FFT s to compute the self magnetostatic demag field Anisotropy applied field and initial magnetization can be varied pointwise and arbitrarily shaped elements can be modeled The current development version OOMMF 1 2 includes Oxs the OOMMF eXtensible Solver Oxs offers users of OOMMF the ability to extend Oxs with their own modules The details of programming an Oxs extension module are found in the OOMMF Programming Manual The extensible nature of the Oxs solver means that its capabilities may be varied as necessary for the problem to be solved Oxs modules distributed as part of OOMMF support full 3D simulations suitable for modeling layered materials thttp math nist gov oommf http math nist gov oommf software html 3http math nist gov oommf doc If you want to receive e mail notification of updates to this project register your e mail address with the wMAG Announcement mailing list http www ctcms nist g
295. root with the appropriate paths on your system cf Section 5 This will set up an association on files with the ovf extension Internet Explorer 3 X apparently ignores the HTML Content Type field so you must repeat this process for each file extension ovf omf ohf obf and svf that you want to recognize This means however that Internet Explorer will make the appropriate association even if the HTML server does not properly set the HTML Content Type field Microsoft Internet Explorer 4 X is integrated with the Windows operating system In ternet Explorer 4 X doesn t offer any means to set up associations between particular file types and the applications which should be used to open them Instead this association is configured within the Windows operating system To set up associations for the OOMMF Vector Field file type on Windows 95 or Windows NT select Settings Control Panel from the Start menu The Control Panel window appears Select View Options to display a dialog box A Windows 98 shortcut to the same dialog box is to select Settings Folder Options from the Start menu Select the File Types tab and proceed as described above for Internet Explorer 3 X Depending on the exact release service patch of your Windows operating system the exact instructions may vary Once you have your browser configured you can test with the following URL http math nist gov MDonahue cubevortex ovf 147 Known Bugs The slice se
296. ross the entire simulation in A m Mz or normalized units mz depending on the setting of the normalize_aveM_output option e Max Spin Ang maximum angle between neighboring spins having non zero magnetization M measured in degrees The definition of neighbor depends on the mesh but for Oxs_RectangularMesh the neighborhood of a point consists of 6 points those nearest forward and backward along each of the 3 coordinate axis directions e Stage Max Spin Ang the largest value of Max Spin Ang obtained across the current stage in degrees e Run Max Spin Ang the largest value of Max Spin Ang obtained across the current run in degrees The three Max Spin Ang outputs are disabled by default In general one should refer instead to the neighboring spin angle outputs provided by the exchange energies How ever for backward compatibility or for simulations without any exchange energy terms the driver spin angle outputs can be enabled by setting the report_max_spin_angle option to to 1 The vector field outputs are e Magnetization magnetization vector M in A m e Spin unit magnetization m This output ignores the vector_field_output_format precision setting instead always exporting at full precision Examples sample mif pulse mif Oxs_MinDriver The Oxs driver for controlling minimization evolvers is Oxs_MinDriver The specify block has the form 80 Specify Oxs_MinDriver name evolver evolver_
297. ry between systems If no command line arguments are passed to the bootstrap application by default it will launch the application mmLaunch Sec 6 Any command line arguments to the bootstrap application that begin with the character modify its behavior For a summary of all command line options recognized by the bootstrap application run tclsh oommf tcl help The command line arguments bg and fg control how the bootstrap behaves after launching the requested application It can exit immediately after launching the requested application in background mode bg or it can block until the launched application ex its fg Each application registers within the OOMMF system whether it prefers to be launched in foreground or background mode If neither option is requested on the command line the bootstrap launches the requested application in its preferred mode The first command line argument that does not begin with the character is interpreted as a specification of which application should be launched As described above this is usually the simple name of an application When a particular version of an application is required though the bootstrap allows the user to include that requirement as part of the specification For example tclsh oommf tcl mmGraph 1 1 will guarantee that the instance of the application mmGraph it launches is of at least version 1 1 If no copy of mmGraph satisfying the version requirement can be f
298. s The lower panel of the Boxsi interactive interface presents Output Destination and Sched ule sub windows that display the current output configuration and allow interactive modifi cation of that configuration These controls are identical to those in the Oxsii user interface refer to the Oxsii documentation Sec 7 1 for details The only difference between Boxsi and Oxsii with respect to outputs is that in practice Boxsi tends to rely primarily on Destination and Schedule commands in the input MIF file Sec 17 1 2 to setup the out put configuration The interactive output interface is used for incidental runtime monitoring of the job Controls The runtime controls provided by the Boxsi interactive interface are a restricted subset of those available in the Oxsii interface If the runtime controls provided by Boxsi are found to be insufficient for a given task consider using Oxsii instead 42 The File menu holds 4 entries Show Console Close Interface Clear Schedule and Exit Oxsii File Show Console brings up a Tcl shell console running off the Boxsi interface Tcl interpreter This console is intended primary for debugging purposes File Close Interface will remove the interface window from the display but leaves the solver running This effect may also be obtained by deselecting the Boxsi interface button in the Threads list in mmLaunch File Clear Schedule will disable all currently active output schedules exactly as if the
299. s Destination lt desttag gt lt appname gt new This command associates a symbolic desttag with an application The tags are used by the Schedule command see below to refer to specific application instances The appname may either be an OOMMF application name e g mmDisp or else a specific application instance in the form application nickname such as mmDisp Spock In the first case the tag is associated with the running instance of the requested application here mmDisp with the lowest OOMMF ID OID that has not yet been associated with another tag If no running application can be found that meets these criteria then a new instance of the application is launched If the appname refers to a specific application instance then the tag is associated with the running instance of the application say mmDisp that has been assigned the specified nickname Name matching is case insensitive If there is no running copy of the application meeting this condition then a new instance of the application is launched and it is assigned the specified nickname The OOMMF account service directory guarantees that there is never more than one instance of an application with a given nickname However as with the object name in the Specify command instances of two different applications e g mmDisp and mmGraph are allowed to share nicknames because their full instance names say mmDisp Spock and mmGraph Spock are unique The Destination commands ar
300. s a result the source code for this implementation is considerably simpler than for Oxs_Demag but the run time performance and memory usage are poorer Oxs_SimpleDemag is included for validation checks and as a base for user defined demagnetization implementations The Specify initialization string for Oxs_SimpleDemag is an the empty string i e Example squarecubic mif e Zeeman Energy Oxs_UZeeman Uniform homogeneous applied field energy This class is frequently used for simulating hysteresis loops The specify block takes an optional multi plier entry and a required field range list Hrange The field range list should be a compound list with each sublist consisting of 7 elements the first 3 denote the x y and z components of the start field for the range the next 3 denote the x y and z components of the end field for the range and the last element specifies the number of linear steps through the range If the step count is 0 then the range consists of the start field only If the step count is bigger than 0 then the start field is skipped over if and only if it is the same field that ended the previous range if any The fields specified in the range entry are nominally in A m but these values are multiplied by multiplier which may be used to effectively change the units For example Specify Oxs_UZeeman multiplier 795 77472 Hrange 59 The applied field steps between 0 mT 5 mT 10 mT and back to 0 mT for
301. s a temporary object via an inlined Specify call The following example should help clarify the use of the script parameter Specify Oxs_StageZeeman script SlidingFieldSpec stage_count 11 proc SlidingFieldSpec stage set xcutoff expr double stage 10 set spec Oxs_ScriptVectorField lappend spec subst atlas atlas script SlidingField xcutoff FI return spec proc SlidingField xcutoff xrel yrel zrel if xrel gt xcutoff return list 0 0 0 return list 2e4 0 0 The SlidingFieldSpec proc is used to generate the initialization string for an Oxs_ScriptVectorField vector field object which in turn uses the SlidingField proc to specify the applied field on a position by position basis The resulting field will be 2 x 10 A m in the positive x direction at all points with relative x coordinate larger than stage 10 and 0 otherwise stage is the stage index which here is one of 0 1 10 For example if stage is 5 then the left half of the sample will see a 2 x 104 A m field directed to the right and the right half of the sample will see none The return value from SlidingFieldSpec in this case will be Oxs_ScriptVectorField atlas atlas script SlidingField 0 5 The atlas reference is to an Oxs_Atlas object defined elsewhere in the MIF file The stage_count parameter lets the Oxs_Driver Sec 7 3 5 know how many stages the Oxs_StageZeeman object wants A value of 0 indicates t
302. s entirely inside the selected region The output values consist of 6 columns the ball center point location and the vz vy and v values averaged across the ball As a special case if the spatial extent of the selected region is two dimensional e g all the sample locations have the same z coordinate then the averaging region is taken to be a disk instead of a ball Similarly if the spatial extent of the selected region is one dimensional then the averaging region is reduced to a one dimensional line segment Note The output columns described above may be suppressed by the defaultpos and defaultvals options Additional columns may be introduced by the index and valfunc options The default averaging type is space axis lt xly lz gt For the average plane and average line averaging types selects which subset of affine subspaces the averaging will be performed over In the plane case the axis represents the normal direction to the planes while for line it is the direction parallel to the lines This parameter is ignored if average is not either plane or line Default value is x ball_radius brad This option is required if average is ball in which case brad specifies the radius of the averaging ball in problem units e g meters If average is not ball then this option is ignored defaultpos lt 0 1 gt By default the output data columns are as described in the descrip tion of the average option above However defaul
303. s specify the entire matrix in the order M11 Myo Miz Ma1 M33 If M is not specified then it is taken to be the identity matrix The offset entry is simply a 3 vector that is added to Ma If offset is not specified then it is set to the zero vector 89 It is frequently the case that the transformation that one wants to apply is not Ma off but rather the inverse i e M a off Provided M is nonsingular this can be accomplished by setting the inverse option to 1 In this case the matrix M M is compared to the identity matrix to check the accuracy of the matrix inversion If any entry in M M differs from I by more than the 8 byte float machine precision typically 2 x 10716 times the value of inverse_slack then an error is raised The default setting for invert_flag is 0 meaning don t invert and the default setting for slack is 128 Here is an example using Oxs_AffineOrientScalarField to rotate a field by 90 coun terclockwise about the z axis Note that the specified atlas is square in x and y with the origin of the atlas coordinates in the center of the atlas volume Specify Oxs_BoxAtlas atlas xrange 250e 9 250e 9 yrange 250e 9 250e 9 zrange 15e 9 15e 9 Specify Oxs_FileVectorField file1 atlas atlas file filel omf Specify Oxs_VecMagScalarField fileimag field filel Specify Oxs_AffineOrientScalarField reflect field fileimag M 010 1 0 0 001 See also the Oxs_AffineOri
304. s that are defined across individual regions of an Oxs Atlas The Specify block has the form Specify Oxs_AtlasVectorField name atlas atlas_spec norm magval multiplier mult default_value vector_field_spec values region1_label vector_field_spec1 region2_label vector_field_spec2 Interpretation is analogous to the Oxs_AtlasScalarField specify block except here the output values are 3 dimensional vectors rather than scalars Thus the values associated with each region are vector fields rather than scalar fields Any of the vector field types described in this Field Objects section may be used As usual one may provided a braced list of three numeric values to request a uniform spatially homogeneous vector field with the indicated value The optional norm parameter causes each vector value to be scaled to have magnitude magval The optional multiplier value scales the field values If both norm and multiplier are specified then the field vectors are first normalized before being scaled by the multiplier value Examples diskarray mif exchspring mif imageatlas mif spinvalve mif Oxs_Script VectorField Conceptually similar to the Oxs_ScriptScalarField scalar field object page 85 except that the script should return a vector as a 3 element list rather than a scalar In addition to the parameters accepted by Oxs_ScriptScalarField Oxs ScriptVectorField also accepts an optional parameter norm If specified the return values fr
305. se arrays are read first from the main configuration file oommf app mmdisp scripts avf2ps config followed by the local customization file oommf app mmdisp scripts local avf2ps config if it exists Lastly any files passed as config options on the command line are input Each of these parameters is interpreted as explained in the mmDisp documentation q v ex cept that avf2ps ignores the misc defaultwindowwidth and misc defaultwindowheight parameters and the following additional parameters are available arrow outlinewidth Width of a colored outline around each arrow this can improve visi bility of an arrow when it is overlayed against a background with color similar to that of the arrow Default value is zero meaning no outline A value of 1 produces an outline with a recommended width and other positive values are scaled relative to this arrow outlinecolor If arrow outlinewidth is positive then this is the color of the arrow outline misc boundarypos Placement of the bounding polygon either back or front i e either behind or in front of the rendered arrows and pixel elements misc matwidth Specifies the width in pixels of a mat frame around the outer edge of the image The mat is drawn in front of all other objects To disable set matwidth to 0 misc matcolor Color of the mat misc width misc height Maximum width and height of the output bitmap in pixels If misc crop is enabled then one or both of these dimensi
306. sed If precess is 0 then precession is disabled and the simulation evolves towards equilibrium along a steepest descent path The default value is 1 The min_timestep and max_timestep parameters provide soft limits on the size of steps taken by the evolver The minimum value may be overridden by the driver if a smaller step is needed to meet time based stopping criteria The maximum value will be ignored if a step of that size would produce a magnetization state numerically indis tinguishable from the preceding state The units for min timestep and max_timestep are seconds Default values are 0 and 10 respectively The optional fixed_spins entry allows the magnetization in selected regions of the simulation to be frozen in its initial configuration The value portion of the entry should be a list with the first element of the list being either an inline atlas definition 67 grouped as a single item or else the name of a previously defined atlas The remainder of the list are names of regions in that atlas for which the magnetization is to be be fixed i e M t M 0 for all time t for all points in the named regions Fields and energies are computed and reported normally across these regions Although any atlas may be used it is frequently convenient to set up an atlas with special regions defined expressly for this purpose The stepsize for the first candidate iteration in the problem run is selected so that the maximum change in th
307. sented by shorter arrows with length determined by a linear scale between zero and the data scale value Similarly the data scale value controls the range of values spanned by the colormap used to color pixels The usual use of the Data Scale entry is to reduce the data scale value so that more detail can be seen in those portions of the vector field which have magnitude less than other parts of the vector field If the data scale value is increased then the length of the arrows in the plot is reduced accordingly If the data scale value is decreased then the length of the arrows is increased until they reach full scale An arrow representing a vector with magnitude larger than the data scale value may be thought of as being truncated to the data scale value The initial default data scale value is usually the maximum vector magnitude in the field so at this setting no arrows are truncated Entering 0 into the data scale box will cause the data scale to be reset to the default value For OVF files Sec 19 1 the default data scale value is set from the ValueRangeMaxMag header line This is typically set to the maximum vector magnitude but this is not guaranteed The data scale control is intended primarily for use with vector fields of varying magnitude e g H fields but may also be used to adjust the pixel display contrast for any field type The Zoom entry controls the spatial scaling of the display The value roughly corresponds to the num
308. shold script_args vectors F Specify Oxs_TimeDriver mO rot Ms Ms stopping _dm_dt 0 01 evolver evolve mesh mesh The base field here is given by the Oxs_ScriptVectorField trap object which pro duces a vector field having a trapezoidal shape with the non zero vectors pointing paral lel to the y axis The orient and rot transformations rotate the shape and the vec tors counterclockwise 90 Additionally the offset option in orient translates the shape 20 nm towards the left The original and transformed fields are illustrated below e e eee eet tt t eee eet te eee et tt aH tee eee eee ee eeeee eee eee tt tt te eee ee tt eee eet tt t teeeee eee t ee eee eee 44 4 et ee ee et et a 4 4 4 4 Original field Rotated field Example sample vecrotate mif Oxs_MaskVectorField Multiplies a vector field pointwise by a scalar vector field the mask to produce a new vector field The Specify block has the form Specify Oxs MaskVectorField name 99 mask scalar_field_spec field vector_field_spec This functionality can be achieved if in a somewhat more complicated fashion with the Oxs_ScriptVectorField class For example given a scalar field mask and a vector field vfield this example using the Oxs MaskVectorField class Specify Oxs_MaskVectorField mask mask field vfield is equivalent to this example using the Oxs_ScriptVectorField class proc
309. sk OOMMF may take up much more disk space This is because on such systems the minimum size of any http purl org tcl home http www itworld com AppDev 1461 UIR000330xvfb file is large as much as 32 KB Since this is much larger than many files in the OOMMF distribution require a great deal of disk space is wasted To build OOMMF software from source code you will need a C compiler capable of handling C templates C exceptions and for the OOMMF eXtensible Solver the C Standard Template Library You will need other software development utilities for your platform as well We do development and test builds on the following platforms although porting to others should not be difficult Platform Compilers Windows Microsoft Visual C Borland C Intel C MinGW g Linux x86 Gnu g Intel C Portland Group pgCC Linux Itanium Intel C Gnu g Mac OS X Gnu g MIPS IRIX 6 SGI MIPSpro C Gnu g SPARC Solaris Sun Workshop C Gnu g System Notes e Linux x86 Both 32 bit x86 and 64 bit x86_64 supported e Windows Microsoft Visual C compiler 6 0 or later required 2 2 Basic Installation Follow the instructions in the following sections in order to prepare OOMMEF software for use on your computer 2 2 1 Download The latest release of the OOMMF software may be retrieved from the OOMMF download page Each release is available in two formats The first format is a gzipped tar
310. spec mesh mesh_spec Ms scalar_field_spec mO vector_field_spec stopping mxHxm torque_criteria stage_iteration_limit stage_iteration_count total_iteration limit total_tteration_count stage_count number_of_stages stage_count_check test checkpoint_file restart_file_name checkpoint_interval checkpoint minutes checkpoint_cleanup cleanup_behavior start_iteration iteration start_stage stage start_stage_iteration stage_iteration start_stage_start_time stage_time start_stage elapsed time stage_elapsed_time start_last_timestep timestep normalize_aveM_output aveMflag report_max_spin_angle report These parameters are the same as those described for the Oxs_TimeDriver class page 77 except that stopping_mxHxm replaces stopping_dm_dt and there is no analogue to stopping time The value for stopping_mxHxm is in A m and may be a grouped list Sec 17 1 3 3 Choice depends on the particulars of the simulation but typical values are in the range 10 to 0 1 Limits in the numerical precision of the energy calculations usually makes it not possible to obtain m x H x m below about 0 01 A m This control can be disabled by setting it to 0 0 As with Oxs_TimeDriver in the older MIF 2 1 format this Specify block supports three additional values basename to control output filenames and output format controls scalar_output_format and vector_field_output_format In the MIF 2 2 format these output controls have been moved into the SetOptions block See th
311. special coloring effects Note The in plane angle quantities are generally best viewed with a colormap that begins and ends with the same color e g Red Green Blue Red The ordering of the colormap can be reversed by selecting the Reverse checkbox For example this would change the Red Black Blue colormap to effectively Blue Black Red Below the Reverse checkbutton in the pixel plot type row is a Opaque checkbutton If this is selected then arrows below the top row in the pixel slice range see slice discussion below will be hidden by the pixel object If disabled then the pixel object is translucent so objects further below are partially visible When there are many vectors in a vector field a display of all of them may be more con fusing than helpful The Subsample column allows the user to request that only a sampling of vectors from the vector field be displayed The Subsample value is roughly the number of vectors along one spatial dimension of the vector field which map to a single displayed vector arrow or pixel Each vector displayed is an actual vector in the vector field the selection of vectors for display is a sampling process not an averaging or interpolation process The subsample rates for arrows and pixels may be set independently A subsample rate of 0 is interpreted specially to display all data This is typically much quicker than subsampling at a small rate e g 0 1 The length of an arrow represen
312. splay mmGraph File x YL Y2 Options Run on stdprob2 75 mif with cellsize 20e 9 Iteration Bx By M Bz E Mx Ms E My Ms E Mz Ms l Energy Overview The application mmGraph provides a data display service similar to that of mmDataT able Sec 11 The usual data source is a running solver but rather than the textual output provided by mmDataTable mmGraph produces 2D line plots mmGraph also stores the data it receives so it can produce multiple views of the data and can save the data to disk Postscript output is also supported Launching mmGraph may be started either by selecting the mmGraph button on mmLaunch or from the command line via tclsh oommf tcl mmGraph standard options net lt 0 1 gt loadfile net lt 0 1 gt Disable or enable a server which allows the data displayed by mmGraph to be updated by another application By default the server is enabled When the server is disabled mmGraph may only input data from a file loadfile Optional list of data ODT files to preload 129 Inputs Input to mmGraph may come from either a file in the ODT format Sec 18 or when net 1 the default is active from a client application typically a running solver The File Open dialog box is used to select an input file Receipt of data from client applica tions is the same as for mmDataTable Sec 11 In either case input data are appended to any previously held data When rea
313. sponding application Only one click is needed though there will be some delay before the launched application displays a window to the user Multiple clicks will launch multiple copies of the application Note The launching is actually handled by the account service directory application Sec 4 which sets the initial working directory to the OOMMF root directory The Threads column is a list of all the OOMMF applications currently running under the account that are registered with the account service directory The list includes both the application name and an ID number by which multiple copies of the same application may be distinguished This ID number is also displayed in the title bar of the corresponding application s user interface window When an application exits its entry is automatically removed from the Threads list Any of the running applications that do not provide their own interface window will be displayed in the Threads list with a checkbutton The checkbutton toggles the display of an interface which mmLaunch provides on behalf of that application The only OOMMF applications currently using this service are the 3D solvers Oxsii and Boxsi Sec 7 the 2D solvers mmSolve2D and batchsolve Sec 10 and the archive application mmArchive Sec 14 These interfaces are described in the documentation for the corresponding appli cations The menu selection File Exit terminates the mmLaunch application and the File Exit All
314. sponding to the closest match If a pixel color doesn t match any of the colormap colors then it is assigned to the default region which is the region paired with the default keyword If default does not explicitly appear in the colormap colors list then universe is made the default region To calculate the distance between two colors each color is first converted to a scaled triplet of floating point red green and blue values r g b where each component lies in the interval 0 1 with 0 0 0 representing black and 1 1 1 representing white For example 0 0 1 is bright blue Given two colors in this representation the distance is computed using the standard Euclidean norm with uniform weights i e the distance between r1 g1 b1 and r2 g2 b2 and is y r r2 g1 92 b bel Since the difference in any one component is at most 1 the distance between any two colors is at most v3 As explained above two colors are considered to match if the distance between them is less than the specified matcherror value If maz_color_distance is sufficiently small then it may easily happen that a pixel s color does not match any of the specified region colors so the pixel would be assigned to the default region On the other hand if maz_color_distance is larger than 3 then all colors will match and no pixels will be assigned to the default region If matcherror is not specified then the default value for maxz_c
315. st parameter name specifies the label attached to this output in the DataTable results the full name will be the Specify block instance name followed by output_name The second parameter source_field specifies the vector field output that the output is derived from The source value should match the label for the source field output as displayed in the Output pane of the Oxsii or Boxsi interactive interface this can also be found in the documentation for the source field Oxs_Ext class If the source field is from the same class as the user output then source can use the short form of the name i e the component following the last otherwise the full name must be used The third parameter select_field references a field that is used to weight the source field to create the scalar output The output is computed according to W select li Vsour li 2 Welect li 6 where the sums are across all cells in the simulation Wselectli is the value of the select field at cell i Vsource is the value of the source field at cell i and indicates the scalar dot product The first three parameters are required the remaining parameters are optional The first of the optional parameters normalize affects the denominator in 6 If norm_request is 1 the default then the output is computed as shown in 6 If norm_request is 0 then instead the denominator is replaced with the number of cells in the simulation
316. t start up an instance of mmArchive and select the ControlPoint check box for mmArchive on the Magnetization schedule in the solver This may be done before starting the calculation Control points are points in the simulation where the applied field is stepped These are typically equilibrium states but depending on the input mif file may be triggered by elapsed simulation time or iteration count e DataTable data may be saved by sending scheduled output from the solver to mmArchive which will automatically save all the data it receives Alternatively mmGraph can perform this function Schedule output to mmGraph as de sired and use either the interactive or automated save functionality of mmGraph Sec 12 You can setup the solver data scheduling before the calculation is started but must wait for the first data point to configure mmGraph before saving any data As a workaround you may configure mmGraph by sending it the initial solver state interactively and then use the Options clear Data menu item in mm Graph to remove the initializing data point Midcourse control e On the mmSolve2D window buttons can stop and restart the calculation Reset Return to beginning of problem LoadProblem Restart with a new problem Run Apply a sequence of fields until all complete Relax Run the ODE at the current applied field until the next control point is reached Pause Click anytime to stop the solver Continue s
317. t Fundamental mesh spatial unit treated as a label The comment marker is not allowed in this label Example value nm e valueunit Fundamental field value unit treated as a label The comment marker is not allowed in this label Example kA m e valuemultiplier Values in the data block are multiplied by this to get true values in units of valueunit This simplifies the use of normalized values e xmin ymin zmin xmax ymax zmax Six separate lines specifying the bounding box for the mesh in units of meshunit This may be used by display programs to limit the display area and may be used for drawing a boundary frame if boundary is not specified e boundary List of x y z triples specifying the vertices of a boundary frame Optional e ValueRangeMaxMag ValueRangeMinMag The maximum and minimum field magnitudes in the data block in the same units and scale as used in the data block These are for optional use as hints by postprocessing programs for example mmDisp will not display any vector with magnitude smaller than ValueRangeMinMag If both ValueRangeMinMag and ValueRangeMaxMag are zero then the values should be ig nored e meshtype Grid structure should be either rectangular or irregular Irregular grid files should specify pointcount in the header rectangular grid files should specify instead xbase ybase zbase xstepsize ystepsize zstepsize
318. t only follows file URLs such as file path to oommf doc userguide userguide Documentation_Viewer_mmHelp html OOMMEF software can be customized See Sec 2 3 2 to use another program to display the HTML help files Launching mmHelp may be launched from the command line via tclsh oommf tcl mmHelp standard options URL The command line argument URL is the URL of the first page home page to be displayed If no URL is specified mmHelp displays the Table of Contents of the OOMMF User s Guide by default 151 Controls Each page of hypertext is displayed in the main mmHelp window Words which are under lined and colored blue are hyperlinks which mmHelp knows how to follow Words which are underlined and colored red are hyperlinks which mmHelp does not know how to follow Moving the mouse over a hyperlink displays the target URL of the hyperlink in the Link line above the display window Clicking on a blue hyperlink will follow the hyperlink and display a new page of hypertext mmHelp keeps a list of the viewed pages in order of view Using the Back and Forward buttons the user may move backward and forward through this list of pages The Home button causes the first page to be displayed allowing the user to start again from the beginning These three buttons have corresponding entries in the Navigate menu Use the menu selection File Open to directly select a file from the file system to be displayed by mmHelp The menu selection
319. t_args is not specified the default value relpt is used When executed the return value from the script should be an integer in the range 1 to n indicating the user defined region in which the point lies or else 0 if the point is not in any of the n regions Region index 0 is reserved for the implicit universe region which is all encompassing The following example may help clarify the discussion proc Octs cellsize x y Zz xmin ymin zmin xmax ymax zmax set xindex expr int floor x xmin cellsize set yindex expr int floor y ymin cellsize set zindex expr int floor z zmin cellsize set octant expr 1 xindext 2 yindext4 zindex if octant lt 1 octant gt 8 return 0 return octant Specify Oxs_ScriptAtlas octant xrange 20e 9 20e 9 yrange 20e 9 20e 9 zrange 20e 9 20e 9 regions VIII V VII VI IV I III II script_args rawpt minpt maxpt script Octs 20e 9 This atlas divides the rectangular volume between 20 20 20 and 20 20 20 nm into eight regions corresponding to the standard octants I through VIII The Octs Tcl procedure returns a value between 1 and 8 with 1 corresponding to octant VIII and 8 to octant II The canonical octant ordering starts with I as the 2 y z space proceeds counterclockwise in the z half space and concludes in the z half space with V directly beneath I VI beneath II etc The ordering computed algorit
320. take a great many steps to obtain an interval large enough to bracket the minimum If minimum _bracket_step is too large then the bracket interval will be unnecessarily generous and many steps may be required to locate the minimum inside the bracketing interval However this value only comes into play when resetting the line minimization direction sequence so the setting is seldom critical It is specified in degrees with default value 0 05 75 If maximum_bracket_step is too small then the minima will be mostly not bracketed and the minimization will degenerate into a type of steepest descent method On the other hand if maximum_bracket_step is too large then the line minimizations may draw the magnetization far away from a local energy minimum i e one on the full 3N dimensional magnetization space eventually ending up in a different more distant minimum The value for maximum_bracket_step is specified in degrees with default value 10 The line minimum_angle_precision and line minimum_relwidth values determine the precision of the individual line minimizations not the total minimization proce dure which is governed by the stopping criteria specified in the driver s Specify block However these values are important because the precision of the line minimizations affects the the line direction sequence orthogonality If both are too coarse then the selected line directions will quickly drift away from mutual orthogonality Convers
321. tant A Note that this is different from the default SolverTaskInit proc which interprets its first argument as the name of a MIF 1 x file to load With this task script a MIF file is read once when the slave is brought up and then each task redefines only the value of A for the simulation and corresponding changes to the output filenames and data table header Finally the Tcl loop structure foreach A A_list TaskInfo AppendTask A A BatchTaskRun A is used to build up a task list consisting of one task for each value of A in A_list defined at the top of the task script For example the first value of A is 10e 13 so the first task will have the label A 10e 13 and the corresponding script is BatchTaskRun 10e 13 The 122 FILE octrlitask tcl This is a sample batch task file with expanded output control Usage example tclsh oommf tcl batchmaster octrltask tcl HH HH H HF OF Every output selection count set SKIP_COUNT 10 Initialize solver This is run at global scope set init_script Text output routine proc MyTextOutput global outtextfile puts outtextfile GetTextData data flush outtextfile Change control point output proc BatchTaskRelaxCallback MyTextOutput Add output on iteration events proc BatchTaskIterationCallback f global solver set count solver GetODEStepCount if count __SKIP_COUNT__ 0 MyTextOutput Substitute SKIP_COUNT in for __SKIP_COUNT
322. tes the mmHelp application The menu Help provides the usual help facilities Known Bugs mmHelp is pretty slow You may be happier using local customization Sec 2 3 2 methods to replace it with another more powerful HTML browser Also we have noticed that the underscore character in the italic font is not displayed or is displayed as a space at some font sizes on some platforms 152 16 Command Line Utilities This section documents a few utilities distributed with OOMMF that are run from the command line Unix shell or Windows DOS prompt They are typically used in pre or post processing of data associated with a micromagnetic simulation 16 1 Bitmap File Format Conversion any2ppm The any2ppm program converts bitmap files from the Portable Pixmap PPM Windows BMP and GIF formats into the Portable Pixmap P3 text format or the uncompressed 24 bits per pixel BMP binary format Additional formats may be available if the Tcl Tk Img package is installed on your system Note OOMMEF support for BMP requires Tk 8 0 or later Launching The any2ppm launch command is tclsh oommf tcl any2ppm standard options f format fmt noinfo o outfile infile where f Force output If the o option is not specified then the output filename is automatically generated by stripping the extension if any off of each input filename and appending a format specific extension e g ppm If f is specified that gen
323. the Oxs_ScriptVectorField documentation page 93 for an example using an atlas specification proc Ellipsoid xrel yrel zrel set xrad expr xrel 0 5 set yrad expr yrel 0 5 set zrad expr zrel 0 5 set test expr xrad x xrad yrad x yrad zrad zrad if test gt 0 25 return 0 return 8 6e5 Specify Oxs_ScriptScalarField script Ellipsoid xrange 0 te 6 yrange 0 250e 9 zrange 0 50e 9 This Oxs_ScriptScalarField object returns 8 6 x 10 if the import x y z lies within the ellipsoid inscribed inside the axes parallel parallelepiped defined by xmin 0 ymin 0 zmin 0 and xmax le 6 ymax 250e 9 zmax 50e 9 and 0 otherwise See also the discussion of the ReadFile MIF extension command in Sec 17 1 2 for an example using an imported image file for similar purposes Below is one more example illustrating the use of the vector_fields option proc DotProduct x1 y1 z1 x2 y2 22 4 return expr x1 x2 y1 y2 z1 z2 Specify Oxs_FileVectorField file1 atlas atlas file filel omf Specify Oxs_UniformVectorField diri11 norm 1 vector 1 1 1 86 Specify Oxs_ScriptScalarField project script DotProduct script_args vectors vector_fields file1 dir111 The scalar field project yields at each point in space the projection of the vector field file1 onto the 1 1 1 direction Examples antidots filled mif ellipsoid fieldproc mif manyregions scriptfields mif manyspher
324. the any2ppm documentation Sec 16 1 for details 7 1 OOMME eXtensible Solver Interactive Interface Oxsii File Options I ae PL Pee a Problem itmpicgtest mif Status Run Bai Destination Schedule Oxs_Demag Field mm rchive lt 4 2 gt Send Oxs_MinDriver Magnetization mmDisp lt 2139 0 gt p 4 Oxs_MinDriver Spin foo or jog W Stage every h Overview The application Oxsii is the graphical interactive user interface to the Oxs micromagnetic computation engine Within the OOMMF architecture see Sec 4 Oxsii is both a server and a client application Oxsii is a client of data table display and storage applications and vector field display and storage applications Oxsii is the server of a solver control service for which the only client is mmLaunch Sec 6 It is through this service that mmLaunch 34 provides a user interface window shown above on behalf of Oxsii A micromagnetic problem is communicated to Oxsii via a MIF 2 file which defines a collection of Oxs_Ext objects that comprise the problem model The problem description includes a segmentation of the lifetime of the simulation into stages Stages mark discontin uous changes in model attributes such as applied fields and also serve to mark coarse grain simulation progress Oxsii provides controls to advance the simulation stopping between iterations between stages or only when the run is complete Throughout the simulation the
325. the machine You can change this by setting the thread_count value in the config platforms file for your platform The default can be overridden at run time by the environment variable OOMMF_THREADS or by the oxsii boxsi command line option threads If NUMA support is possible on your platform see Parallelization Sec 2 3 4 below then the next line of thread info will indicate whether or not the build process will create NUMA aware Oxs solvers After the thread info oommf tcl platform reports the directory that OOMMF will use to write temporary files This directory is used for example to transfer magnetization data from the micromagnetic solvers to the mmDisp display module You must have write access to this directory If you don t like the OOMMF default you may change it via the path directory temporary setting in the config platforms file for your platform Or you can set the environment variable OOMMF_TEMP which will override all other settings If any environment variables relevant to OOMMEF are set then oommf tcl platform will report these next followed finally by any warnings about possible problems with your Tcl Tk installation such as if you are missing important header files If oommf tcl platform indicates problems with your Tcl Tk installation it may be easiest to re install Tcl Tk taking care to perform a conventional installation OOMMF deals best with conventional Tcl Tk installations If you do not have the p
326. the scalar values are the magnitude v r of the vector values at each point r pertran xoff yoff zoff Translates field with respect to location coordiates by amount zoff yoff zoff in a periodic fashion For example if zoff yoff zoff is 50e 9 0 0 then a vector v at position rz ry rz in the original file is positioned instead at rz 50e 9 ry rz in the output file If the spatial extent of the x coordinate in the input file runs from gmin to maz and if rx 50e 9 is larger than rmaz then v will be placed at rz 50e 9 xmaz xmin instead Translations are rounded to the nearest full step aside from any clipping the output file has the exact same spatial extent and sample locations as the original file If both translation and clipping are requested then the clipping is applied after the translation q Quiet operation don t print informational messages rpertran rxoff ryoff rzoff Similar to pertran except the offsets rxoff ryoff rzoff are interpreted as offsets in the range 0 1 taken relative to the spatial extents of the zx y and z coordinates For example if smax rmin 500e 9 then an rxoff value of 0 1 is equivalent to an zoff value of 50e 9 159 subsample period Reduce point density in output by subsampling input with specified period along x y and z axes For example if period is 2 then the output will have only 1 8th as many points as the input This control is only available for i
327. the system vender There are also binary releases of Tcl Tk for a number of systems available from ActiveState under the name ActiveTcl Alternatively one may download the sources for Tcl and Tk from the Tcl Developer Xchange and build and install Tcl Tk from source The Tcl Tk build follows the usual Unix configure make make install build convention Compiler Optimization Options On most systems OOMMF builds by default with relatively unaggressive compiler optimization options As discussed earlier Optimiation Sec 2 3 3 you may edit the appropriate oommf config platforms file to change the default compilation options However on some common systems e g Linux some BSD variants OOMMF will try to deduce the hardware architecture i e the CPU subtype such as Pentium 3 vs Pentium 4 and apply architecture specific options to the compile commands This is probably what you want if OOMMF is to be run only on the system on which it was built or if it is run on a homogeneous cluster If instead you intend to run OOMMEF on a heterogeneous cluster you may need to restrict the compiler options to those supported across your target machines In that case open the appropriate configuration file in the oommf config platforms directory and look for the lines You can override the GuessCPU results by directly setting or unsetting the cpuopts variable e g set cpuopts list march athlon or unset cpuopts
328. the value of the closest point on the boundary of the image If ext is error the default then an error is raised if a value is needed for any point outside the image Examples rotatecenterstage mif sample reflect mif The available vector field objects are Oxs_UniformVectorField Returns the same constant value regardless of the import posi tion The Specify block takes one required parameter vector which is a 3 element list of the vector to return and one optional parameter norm which if specified adjusts the size of export vector to the specified magnitude For example Specify Oxs_UniformVectorField norm 1 vector 1 1 1 This object returns the unit vector a a a where a 1 3 regardless of the import position This class is frequently embedded inline to specify spatially uniform quantities For example inside a driver Specify block we may have Specify Oxs_TimeDriver mO Oxs_UniformVectorField vector 1 0 0 i As discussed in the MIF 2 documentation Sec 17 1 3 2 page 188 when embedding Oxs_UniformVectorField or Oxs_UniformScalarField objects a notational short hand is allowed that lists only the required value The previous example is exactly equivalent to 92 Specify Oxs_TimeDriver mO 1 0 O where an implicit Oxs_UniformVectorField object is created with the value of vector set to 1 0 0 Examples sample mif cgtest mif Oxs_AtlasVectorField Declares vector value
329. then the output file will also contain an explicit boundary polygon If clipping is active then the output boundary polygon is formed by moving the vertices from the input boundary polygon as necessary to bring them into the clipping region This is arguably not correct in particular for boundary edges that don t run parallel to a coordinate axis 16 4 Making Bitmaps from Vector Fields avf2ppm The avf2ppm utility converts a collection of vector field files e g omf ovf into color bitmaps suitable for inclusion into documents or collating into movies The command line arguments control filename and format selection while plain text configuration files modeled after the mmDisp Sec 13 configuration dialog box specify display parameters Launching The avf2ppm launch command is 160 tclsh oommf tcl avf2ppm standard options config file f filter program format lt P3 P6 B24 gt ipat pattern opatexp regexp opatsub sub v level infile where config file User configuration file that specifies image display parameters This file is discussed in detail below f Force overwriting of existing output files By default if avf2ppm tries to create a file say foo ppm that already exists it generates instead a new name of the form foo ppm 000 or foo ppm 001 or foo ppm 999 that doesn t exist and writes to that instead The f flag disallows alternate filename generation and overwrites fo
330. they will appear in the argument list in front of the script_args values The following is equivalent to the preceding example Specify ScriptScalarField Ms script_args rawpt script SatMag 20e 9 8e5 5e5 proc SatMag zheight Msi Ms2 x yz if z lt zheight return Ms1 return Ms2 Notice in this case that the script value is wrapped in curly braces so that the string SatMag 20e 9 8e5 5e5 will be treated as the single value associated with the label script 193 As seen in the earlier example using the Vortex Tcl proc support procedures in MIF 2 1 files will frequently make use of the Tcl expr command If you are using Tcl version 8 0 or later then the cpu time required by the potentially large number of calls to such proce dures can be greatly reduced by grouping the arguments to expr commands in curly braces as illustrated in the Vortex example The braces aid the operation of the Tcl byte code compiler although there are a few rare situations involving multiple substitution where such bracing cannot be applied See the Tcl documentation for the expr command for details Sometimes externally defined data can be put to good use inside a Tcl support proc as in this example Lay out a 6 x 16 mask at global scope set mask 11 Be PrP ee BPP Pe PrPrPr re Pre PrP Pe Be PrP rPe oOOoOOrRrRF oOOoOOrRrRF Oo OOrRFR F oO OOrFRF FE oOoOOrRrRF GO OOrRFR F Be PrP ee BPRPRPrReRe eB PPP Rr re Pe PrP Pe Be
331. time to upgrade to one that does OOMMF 1 2 requires a compiler capable of compiling source code which uses C exceptions Compiling Sec 2 2 3 with gcc eges produces syntax errors on lines involving auto_ptr templates This is known to occur on RedHat 5 2 systems The auto_ptr definition in the system STL header file memory located on RedHat 5 2 systems in the directory usr include g is disabled by two if statements One solution is to edit this file to turn off the if checks If you do this you will also have to fix two small typos in the definition of the release member function When compiling Sec 2 2 3 there is an error message arising from system include directories being too early in the include search path Try adding the offending direc tories to the program_compiler_ct _system_include_path property in the platform file e g config SetValue program_compiler_c _system_include_path list usr include usr local include On Solaris gcc reports many errors like ANSI C forbids declaration XSetTransientForHint with no type On many Solaris systems the header files for the X Window System are not ANSI compliant and gcc complains about that To work around this problem edit the file oommf config platforms solaris tcl to add the option fpermissive to the gcc command line On Windows when first starting oommf tcl there is an error Error launching mmLaunch version 1 x x x couldn t execute
332. tion options 2 3 1 Reducing Disk Space Usage To delete the intermediate files created when building the OOMMEF software from source code use pimake Sec 16 15 to build the target objclean in the root directory of the OOMMF distribution tclsh oommf tcl pimake objclean Running your platform strip utility on the OOMMF executable files should also reduce their size somewhat 2 3 2 Local Customizations OOMMEF software supports local customization of some of its features All OOMMF pro grams load the file config options tcl which contains customization commands as well as editing instructions As it is distributed config options tcl directs programs to also load the file config local options tcl if it exists Because future OOMMEF releases may overwrite the file config options tcl permanent customizations should be made by copying config options tcl to config local options tcl and editing the copy It is 10 recommended that you leave in the file config local options tcl only the customization commands necessary to change those options you wish to modify Remove all other op tions so that overwrites by subsequent OOMMF releases are allowed to change the default behavior Notable available customizations include the choice of which network port the host service directory application Sec 4 uses and the choice of what program is used for the display of help documentation By default OOMMEF software uses the application mmHelp Sec
333. tions between the control interface of Oxsii and the actual com putation engine If Oxsii is sending out data to two or more data display services every iteration the network traffic from that data can crowd out the receipt of control messages from the control interface You may observe this as a long delay between the time you click the Pause button and the time the solver stops iterating This bug first appeared in Tcl release 8 0 3 and remained through Tcl release 8 1 1 It is fixed in Tcl releases 8 2 and later which we recommend for OOMMF users on Windows 9X systems Other platforms do not have this problem If Tcl version 7 5 is in use and Oxsii processes a Destination command in a MIF file and in response launches another application then Oxsii will not be able to fully terminate until the launched application also terminates You might notice this in mmLaunch where an Oxsii will remain in the Threads column long after it has apparently exited This glitch is due to a bug in Tcl s exec command in version 7 5 that has long been fixed Use a more recent Tcl release to avoid the problem 7 2 OOMME eXtensible Solver Batch Interface boxsi Fil File Run Relax Step Pause Problem tmp sample mif Status Run Stage 3 10 Output Destination Schedule DataTable mmAarchive lt 4 1 gt Send 7 Oxs_Cubic nisotropy Nickel Field mmDataTable lt 5 0 gt Oxs_Demag Field W Step every 5 W Stage every fi 3
334. to interactively adjust the applied field sequence Each click on the Field button advances forward one step through the specified schedule while Field reverses that process In general the step direction is not related to the magnitude of the applied field Also note that hitting these buttons does not generate a ControlPoint event In particular if you are manually accelerating the progress of the solver through a hysteresis loop and want to send non ControlPoint data to a display or archive widget before advancing the field then you must use the appropriate Interactive Output button The second row of buttons in the interaction control panel TotalField Magnetization and DataTable allow the user to view the current state of the solver at any time These buttons cause the solver to send out data of the corresponding type to all applications for which the Interactive schedule button for that data type has been selected as discussed in the Outputs section above At the far right of the solver controls is the Exit button which terminates mmSolve2D Simply closing the user interface window does not terminate mmSolve2D but only closes the user interface window To kill the solver the Exit button must be pressed Details Given a problem description mmSolve2D integrates the Landau Lifshitz equation 10 12 dM yla 2M x He 7H YIM x Heg M M x M x He 5 where M isthe pointwise magnetization A m He is th
335. tpos 0 may be used to omit the columns indicating the averaging position defaultvals lt 0 1 gt By default the output data columns are as described in the descrip tion of the average option above However defaultvals 0 may be used to omit the columns containing the averaged vz vy and v values In particular this may be useful in conjunction with the valfunc option filesort method Specifies the sorting order to apply to the input file list This order is important when using the onefile option since it controls the order in which the rows from the various input files are concatenated Method should be either the keyword none or else a valid option string for the Tcl command lsort e g ascii 155 decreasing Note that the lsort sort options all begin with a hyphen and that if you want to use multiple options they must be grouped as one element to filesort by for example placing quotes around the list The default value is dictionary if the ipat option is specified or none otherwise headers lt full collapse none gt Determines the style of headers written to the output ODT file s The full style default provides the standard headers as described in the ODT documentation Sec 18 Specifying none produces raw data lines without any headers The collapse style is used with multiple input files and the onefile output option to concatenate output with no ODT header information bet
336. tput produced by mmSolve2D include e Iteration The iteration count of the ODE solver e Field Updates The number of times the ODE solver has calculated the effective field e Sim Time ns The elapsed simulated time e Time Step ns The interval of simulated time spanned by the last step taken in the ODE solver e Step Size The magnitude of the last step taken by the ODE solver as a normalized value This is currently the time step in seconds multiplied by the gyromagnetic ratio times the damping coefficient times Ms 109 e Bx By Bz mT The z y and z components of the nominal applied field see Sec 17 3 5 e B mT The magnitude of the nominal applied field always non negative e m x hl The maximum of the point wise quantity M x Heg M2 over all the spins This torque value is used to test convergence to an equilibrium state and raise control point torque events e Mx Ms My Ms Mz Ms The z y and z components of the average magnetiza tion of the magnetically active elements of the simulated part e Total Energy J m The total average energy density for the magnetically active elements of the simulated part e Exchange Energy J m The component of the average energy density for the magnetically active elements of the simulated part due to exchange interactions e Anisotropy Energy J m The component of the average energy density for the magnetically active elements of the simulate
337. try in the Options Configure dialog box The units are pixels Long curves will be rendered more quickly especially on Windows if the curve width is set to 1 As mentioned earlier mmGraph stores in memory all data it receives Over the course of a long run the amount of data stored can grow to many megabytes This storage can be limited by specifying a positive gt 0 value for the Point buffer size entry in the Op tions Configure dialog box The oldest records are removed as necessary to keep the total number of records stored under the specified limit A zero value for Point buffer size is interpreted as no limit The storage size of an individual record depends upon several factors including the number of items in the record and the version of Tcl being used Data erasures may not be immediately reflected in the graph display At any time the point buffer storage may be completely emptied with the Options clear Data command The Options Stop Autosave selection will turn off the auto save feature if currently active Also on this menu is Options Rescale which autoscales the graph axis limits from the selected data This command ignores but does not reset the Auto Scale setting in the Options Configure dialog box The Rescale command may also be invoked by pressing the Home key The Options Break Curves item inserts a curve break record into the point buffer 131 causing a break in each curve after the current point This
338. ts are no longer supported Instead there is a new top level extension command SetOptions where these options are declared The SetOptions block also supports new options for controlling output vector field mesh type rectangular or irregular and scalar field output format 3 In the MIF 2 1 format MIF files are processed in a two pass mode During the first pass Specify commands simply store the contents of the Specify blocks without creating any Oxs_Ext objects The Oxs_Ext objects associated with each Specify block are created in the second pass from the data stored in the first pass In the MIF 2 2 format this is replaced with a one pass mode where Oxs_Ext objects are created at the time that the Specify commands are parsed This processing model is more intuitive for MIF file authors but has two main consequences The first is that in MIF 2 1 format files Tclprocs that are used only inside Specify commands can be placed anywhere inside the MIF file for example commonly at the end because they won t be called during the first pass As long as they are defined at any point during the first pass they will be available for use in the second pass In contrast in the MIF 2 2 format Tclprocs definitions must generally be moved forward before any references in Specify blocks The second consequence is that Oxs_Ext objects defined by Specify commands are available for use inside the MIF file This allows support for the two new commands dis
339. ts the magnitude of the vector field All arrows are drawn with a length between zero and full scale By default the full scale arrow length is computed so that it covers the region of the screen that one displayed vector is intended to represent given the current subsample rate Following this default arrows do not signifi 137 cantly overlap each other yet all non zero portions of the vector field have a representation in the display Similarly pixels are drawn with a default size that fills an area equal to the region of the screen one pixel is intended to represent given the pixel subsample rate The Size column allows the user to independently override the default size of pixels and full scale arrows A value of 1 represents the default size By changing to a larger or smaller Size value the user may request arrows or pixels larger or smaller than the default size Below the Arrow and Pixel Controls are several additional controls The Data Scale entry affects the data value scaling As described above all arrows are displayed with length between zero and full scale The full scale arrow length corresponds to some scalar value of the magnitude of the vector field The Data Scale entry allows the user to set the value at which the drawn arrow length goes full scale Any vectors in the vector field with magnitude equal to or greater than the data scale value will be represented by arrows drawn at full scale Other vectors will be repre
340. ues include x y z xy angle xz angle yz angle and slice The Options Configure dialog presents the complete list of allowed quantities which may be image dependent arrow colorreverse The colorreverse value should be 1 or 0 signifying to reverse or not reverse respectively If reverse is selected then the colormap ordering is inverted changing for example Blue White Red into Red White Blue This corresponds to the Reverse control in the Options Configure 142 arrow colorphase The phase is a real number between 1 and 1 that provides a translation in the selected colormap For the xy angle xz angle and yz angle color quantities this displays as a rotation of the colormap e g setting colorphase to 0 333 would effectively change the Red Green Blue Red colormap into Green Blue Red Green For the other color quantities it simply shifts the display band saturating at one end For example setting colorphase to 0 5 changes the Blue White Red colormap into White Red Red If both inversion and phase adjustment are requested then inversion is applied first arrow size Size of the arrows relative to the default size represented as 1 0 pixel Most of the pixel configuration elements have analogous arrow configuration ele ments and are interpreted in the same manner The exception is the pixel opaque element which is discussed next Note too that the auto subsampling rate for pixels is considerably denser than for arrows
341. ultiplier mult offset off viewplane view atlas atlas_spec xrange min xmax yrange ymin ymax zrange zmin zmar exterior ext_flag The image is interpreted as a monochromatic map yielding a scalar field with black corresponding to zero and white to one if invert is 0 the default or with black corresponding to 1 and white to 0 if invert is 1 Color images are converted to grayscale by simply summing the red green and blue components A multiplier option is available to change the range of values from 0 1 to 0 mult after which the offset value if any is added The viewplane is treated in the same manner as the viewplane option in the Oxs_ImageAtlas class and should likewise take one of the three two letter codes xy default zx or 91 yz The spatial scale is adjusted to fit the volume specified by either the atlas or xrange yrange zrange selections If the specified volume does not fill the entire simulation volume then points outside the specified volume are handled as deter mined by the exterior setting which should be either a floating point value or one of the keywords boundary or error In the first case the floating point value is treated as a default value for points outside the image and should have a value in the range 0 1 The multiplier and offset adjustments are made to this value in the same way as to points inside the image If ext_flag is boundary then points outside the image are filled with
342. un 171 Launching The mag2hfield launch command is tclsh oommf tcl mag2hfield standard options component all anisotropy demag exchange total zeeman data energy field energyfmt fmt fieldstep mif_file omf_file omf_file2 where component all anisotropy demag exchange total zeeman Specify all energy field components that are desired Optional default is total which is the sum of the crystalline anisotropy demagnetization self magnetostatic exchange and Zeeman applied field terms data energy field Calculate energies H fields or both Energy values are printed to stdout H fields are written to files as described below Optional the default is energy field energyfmt fmt Output C printf style format string for energy data Optional The default format string is Zs fieldstep Applied field step index following the schedule specified in the input MIF file 0 denotes the initial field Optional default is 0 mif_file MIF micromagnetic problem specification file mif Required omf_file Magnetization state file This can be in any of the formats accepted by the avfFile record of the input MIF file Required omf_file2 Optional additional magnetization state files The H field output file format is determined by the Total Field Output Format record of the input MIF 1 1 file Sec 17 3 The output file names are constructed using the form bas
343. undary then the value used is the point on the boundary of the input vector field that is closest to the exterior point The default setting for ext_flag is error which raises an error if there are any exterior points The magnitude of the field can be modified by the optional norm and multiplier attributes If the norm parameter is given then each vector in the field will be renor malized to the specified magnitude If the multiplier parameter is given then each vector in the field will be multiplied by the given scalar value If the multiplier value is negative the field direction will be reversed If both norm and multiplier are given then the field vectors are renormalized before being scaled by the multiplier value Examples stdprob3 mif yoyo mif Oxs_RandomVectorField Similar to Oxs_RandomScalarField q v but defines a vector field rather than a scalar field that varies spatially in a random fashion The Specify block has the form Specify Oxs_RandomVectorField name min_norm minvalue maxnorm mazvalue cache grid mesh_spec The Specify block takes two required parameters min_norm and max_norm The vectors produced will have magnitude between these two specified values If min_norm max_norm then the samples are uniformly distributed on the sphere of that ra dius Otherwise the samples are uniformly distributed in the hollow spherical vol 95 ume with inner radius min_norm and outer radius max_norm There is also
344. ural units are radians or radians second Inside the Specify block however the error_rate and absolute_step_error are specified in degrees nanosecond and degrees respectively they are converted appropriately inside the code before use The relative_step_error is a dimensionless quantity representing a proportion between 0 and 1 The error check controlled by each of these three quantities may be disabled by setting the quantity value to 1 They are all optional with default values of 1 for error_rate 0 2 for absolute_step_error and 0 2 for relative _step_error The headroom quantity should lie in the range 0 1 and controls how conservative the code will be in stepsize selection If headroom is too large then much computation time will be lost computing candidate steps that fail the error control tests If headroom is small then most candidate steps will pass the error control tests but computation time may be wasted calculating more steps than are necessary The default value for headroom is 0 85 68 In addition to the above error control tests a candidate step will also be rejected if the total energy after adjusting for effects due to any time varying external field is found to increase In this case the next candidate stepsize is set to one half the rejected stepsize The Oxs_EulerEvolve module provides five scalar outputs and three vector field out puts The scalar outputs are e Max dm dt maximum dm dt in degrees per
345. user clicked through the interactive schedule interface one output and destination at a time and disabled each schedule enabling checkbutton The final entry File Exit Boxsi terminates the Boxsi solver and closes the interface window Note that there is no File Load menu item the problem specification file must be declared on the Boxsi command line The Help menu provides the usual help facilities The row of buttons immediately below the menu bar provides simulation progress con trol These buttons Run Relax Step and Pause become active once the micromagnetic problem has been initialized These buttons allow the user to change the run state of the solver In the Pause state the solver sits idle awaiting further instructions If Step is se lected then the solver will move forward one iteration and then Pause In Relax mode the solver takes at least one step and then runs until it reaches a stage boundary at which point the solver is paused In Run mode the solver runs until the end of the problem is reached When the problem end is reached the solver will either pause or exit depending upon the setting of the exitondone command line option Normally the solver progresses automatically from problem initialization into Run mode but this can be changed by the pause command line switch Interactive output is available in all modes the scheduled outputs occur appropriately as the step and stage counts advance Directly below the ru
346. verTaskCleanup accept an arbitrary argument list args which is copied over from the args argument to the BatchTaskRun and BatchTaskLaunch procs in batchsolve tcl Typically one copies the default procs as needed into a task script and makes appropriate modifications You may re define these procs either before or after sourcing batchsolve tcl See Sec 10 2 2 4 for example scripts 116 10 2 2 2D Micromagnetic Solver Batch Scheduling System Overview The OBS supports complex scheduling of multiple batch jobs with two applications batch master and batchslave The user launches batchmaster and provides it with a task script The task script is a Tcl script that describes the set of tasks for batchmaster to accomplish The work is actually done by instances of batchslave that are launched by batchmaster The task script may be modeled after the included simpletask tcl or multitask tcl sample scripts Sec 10 2 2 4 The OBS has been designed to control multiple sequential and concurrent micromagnetic simulations but batchmaster and batchslave are completely general and may be used to schedule other types of jobs as well 10 2 2 1 Master Scheduling Control batchmaster The application batchmaster is launched by the command line tclsh oommf tcl batchmaster standard options task_script host port task script is the user defined task job definition Tcl script host specifies the network address for the master to use default is l
347. vice for the type of output selected The user may select from this list those applications to which the selected type of output should be sent For each application selected a final interface is displayed in the Schedule subpanel Through this interface the user may set the schedule according to which the selected type of data is sent to the selected application for display or storage The schedule is described relative to events in mmSolve2D An Iteration event occurs at every step in the solution of the ODE A ControlPoint event occurs whenever the solver determines that a control point specification is met Control point specs are discussed in the Experiment parameters paragraph in the MIF 1 1 documentation Sec 17 3 and are triggered by solver equilibrium simulation time and iteration count conditions An Interactive event occurs for a partic ular output type whenever the corresponding Interactive Outputs button is clicked in the Runtime Control panel The Interactive schedule gives the user the ability to interactively force data to be delivered to selected display and storage applications For the Iteration and ControlPoint events the granularity of the output delivery schedule is under user control For example the user may elect to send vector field data describing the current magnetiza tion state to an mmDisp instance for display every 25 iterations of the ODE rather than every iteration The quantities included in DataTable ou
348. way without being interpreted The primary use of Ignore is to temporarily com ment out i e disable Specify blocks OOMMEFRootDir This command takes no arguments and returns the full directory path of the OOMMF root directory This is useful in conjunction with the ReadFile com mand for locating files within the OOMMF hierarchy and can also be used to place output files File paths must be created directly since the Tcl file command is not accessible inside safe interpreters For example set outfile OOMMFRootDir data myoutput In this context one should always use Tcl path conventions In particular use forward slashes to separate directories Parameter The Oxs interfaces Oxsii Sec 7 1 and Boxsi Sec 7 2 allow specified variables in the MIF file to be set from the command line via the parameters option This functionality is enabled inside the MIF file via the Parameter command Parameter varname optional_default_value Here varname is the name of a variable that may be set from the command line If it is not set on the command line then the variable is set to the optional default value if any or otherwise an error is raised An error is also raised if a variable set on the command line does not have a corresponding Parameter command in the MIF file See also the notes on variable substitution Sec 17 1 4 below 183 Random Returns a pseudo random number in the interval 0 1 using a C library random numb
349. ween the segments index label units valexpr Adds an input file based index column to the output where label is the column header units is a string displayed as the column units header and valexpr is a Tcl expr expression that may include the special variables i f1 f2 d1 d2 here i is the 0 based index of the file in the list of input files f1 is the first number appearing in the input filename f2 is the second number appearing in the input filename d1 is the first number appearing in the Desc fields in the header of the input file etc For example if there are two input files named foo 100 ovf and and foo 101 ovf then setting valexpr to abs f 1 1 would yield a column with the value 101 for all lines coming from foo 100 ovf and the value 102 for all lines coming from foo 101 ovf We use the Tcl expr function abs because the leading hyphen in foo 100 ovf gets interpreted as a minus sign so f1 is extracted as 100 On Unix systems the valexpr string should be surrounding by single quotes in order to forestall interpolation of the special variables by the shell On Windows the valexpr string should be surrounded by double quotes as usual to protect embedded spaces Multiple instances of the index option on the command line will result in multiple columns in the output file in the order specified The index columns if any will be the first columns in the output file ipat pattern Specify input files using
350. wo types of evolvers time evolvers which track Landau Lifshitz Gilbert dy namics and minimization evolvers which locate local minima in the energy surface through direct minimization techniques Evolvers are controlled by drivers Sec 7 3 5 and must be matched with the appropriate driver type i e time evolvers must be paired with time drivers and minimization evolvers must be paired with minimization drivers The drivers hand a magnetization configuration to the evolvers with a request to advance the configura tion by one step also called an iteration It is the role of the drivers not the evolvers to determine when a simulation stage or run is complete Specify blocks for evolvers contain parameters to control all aspects of individual stepwise evolution but stopping criteria are communicated in the Specify block of the driver not the evolver There are currently three time evolvers and one minimization evolver in the standard OOMMF distribution The time evolvers are 0xs_EulerEvolve 0xs_RungeKuttaEvolve and Oxs_SpinXferEvolve The minimization evolver is Oxs_CGEvolve Oxs_EulerEvolve Time evolver implementing a simple first order forward Euler method with step size control on the Landau Lifshitz ODE 10 12 dM lyla ali x Heg T JIM x Her ce where M is the magnetization Heg is the effective field y is the Landau Lifshitz gyromagnetic ratio and a is the damping constant The Gilbert form M x M x Her 2 dM
351. xchange coefficient A Here two cells are adjacent if they lie in each other s 6 neighborhood If a pair is found to have a non zero exchange coefficient then A is drawn uniformly from the range Amin Amax The exchange energy is computed using 1 the formula used by the Oxs_Exchange6Ngbr energy object The value Aij for each pair of cells is determined during problem initialization and is held fixed thereafter The limits A_lower_bound and A_upper_bound may be any real 58 numbers negative values may be used to weaken the exchange interaction arising from other exchange energy terms The only restriction is that A_lower_bound must not be greater than A_upper_bound The linkprob value probability must lie in the range 0 1 Example randexch mif e Self Magnetostatic Energy Oxs_Demag Standard demagnetization energy term which is built on the assump tion that the magnetization is constant in each cell and computes the average demagnetization field through the cell using formulae from 2 15 and convolu tion via the Fast Fourier Transform The Specify initialization string should be an empty string typically denoted by Examples sample mif cgtest mif Oxs_SimpleDemag This is the same as the 0xs_Demag object except that the im plementation does not use any of the of the symmetries inherent in the demagne tization kernel or special properties of the Fourier Transform when applied to a real non complex function A
352. xes in meters Oxs_BoxAtlas is a particular type of Oxs Atlas and mark the location of the Oxs_BoxAtlas initialization string which is omitted because it is not pertinent to the present discussion 17 1 3 2 Oxs_Ext referencing The atlas value in the mesh Specify block of the pre ceding example refers to an earlier Oxs_Ext object Oxs BoxAtlas myatlas It frequently occurs that one Oxs_Ext object needs access to another Oxs_Ext object In this example the mesh object mymesh needs to query the atlas object myatlas in order to know the extent of the space that is to be gridded The atlas object is defined earlier in the MIF input file by its own separate top level Specify block and the mesh object refers to it by simply specifying its name Here the full name is used but the short form myatlas would suffice provided no other Oxs_Ext object has the same short name Alternatively the Oxs_RectangularMesh object could define an Oxs_BoxAtlas object inline Specify Oxs_RectangularMesh mymesh atlas Oxs_BoxAtlas 188 cellsize 5e 9 5e 9 5e 9 In place of the name of an external atlas object a two item list is provided consisting of the type of object here Oxs_BoxAtlas and the corresponding initialization string The initialization string is provided as a sublist with the same format that would be used if that object were initialized via a separate Specify block More commonly embedded Oxs_E
353. xible programmer s interface so that people developing new code can swap their own code in and out as desired The main contributors to OOMMF are Mike Donahue and Don Porter In order to allow a programmer not familiar with the code as a whole to add modifications and new functionality we feel that an object oriented approach is critical and have settled on C as a good compromise with respect to availability functionality and portability In order to allow the code to run on a wide variety of systems we are writing the interface and glue code in Tcl Tk This enables our code to operate across a wide range of Unix platforms Windows NT and Windows 9X The code may be modified at 3 distinct levels At the top level individual programs interact via well defined protocols across network sockets One may connect these modules together in various ways from the user interface and new modules speaking the same protocol can be transparently added The second level of modification is at the Tcl Tk script level Some modules allow Tcl Tk scripts to be imported and executed at run time and the top level scripts are relatively easy to modify or replace At the lowest level the C source is provided and can be modified although at present the documentation for this is incomplete cf the OOMMF Programming Manual The first portion of OOMMF released was a magnetization file display program called mm Disp A working release of the complete OOMMF p
354. xpand wildcards before handing control over to the invoked application so the ipat option is not needed although it is useful in case of a command line too long 161 error DOS does not do this expansion so you must use ipat to get wildcard expansion in Windows As each input file is processed a name for the output file is produced from the input filename by rules determined by handing the opatexp and opatsub expressions to the Tcl regsub command Refer to the Tcl regsub documentation for details but essentially whatever portion of the input filename is matched by the opatexp expression is removed and replaced by the opatsub string The default opatexp expression matches against any filename extension of up to 3 characters and the default opatsub string replaces this with the extension ppm or bmp If you have command line image processing filter programs e g ppmtogif part of the NetPBM package then you can use the filter option to pipe the output of avf2ppm through that filter before it is written to the output file specified by the opat expressions If the processing changes the format of the file e g ppmtogif converts from PPM to GIF then you will likely want to specify a opatsub different from the default Here is an example that processes all files with the omf extension sending the output through ppmtogif before saving the results in files with the extension gif tclsh oommf tcl avf2ppm ipat
355. xs_TimeDriver block The arguments X y and z are coordinates relative to the min and max range of each dimension e g 0 lt x lt 1 where x corresponds to xmin x 1 corresponds to xmax proc UpDownSpin xyz if x lt 0 45 return 0 1 0 elseif x gt 0 55 return 0 1 0 else return 0 0 1 HH H Specify Oxs_TimeDriver evolver Oxs_RungeKuttaEvolve stopping _dm_dt 0 01 mesh mesh Ms 8e5 comment implicit Oxs_UniformScalarField object mO Oxs_ScriptVectorField script UpDownSpin norm 1 atlas WorldAtlas ame basename example Default outputs Destination hystgraph mmGraph Hysteresis Destination monitor mmGraph new 200 Destination archive mmArchive Schedule DataTable hystgraph Stage 1 Schedule DataTable monitor Step 5 Schedule DataTable archive Stage 1 Schedule Oxs_TimeDriver Magnetization archive Stage 3 Schedule Oxs_RungeKuttaEvolve Total field archive Stage 3 Figure 7 Example MIF 2 1 file 17 2 MIF 2 2 The MIF 2 2 format introduced with OOMMF 1 2a4 is a minor modification to the MIF 2 1 format MIF 2 2 provides a few additional commands and is mostly backwards compatible with MIF 2 1 except as detailed below 17 2 1 Differences between MIF 2 2 and MIF 2 1 Formats 1 The first line of a MIF 2 2 file must be MIF 2 2 2 The basename scalar_output_format and vector_field_output_format options to the Oxs_TimeDriver and Oxs_MinDriver objec
356. xt objects are used to initialize spatially varying quan tities For example Specify Oxs_UniaxialAnisotropy axis Oxs_RandomVectorField min_norm 1 max_norm 1 K1 Oxs_UniformScalarField value 530e3 The magneto crystalline anisotropy class Oxs_UniaxialAnisotropy supports cellwise vary ing K1 and anisotropy axis directions In this example the anisotropy axis directions are randomly distributed To initialize its internal data structure OxsUniaxialAnisotropy creates a local Oxs_RandomVectorField object This object is also a child of the Oxs_Ext hi erarchy which allows it to be constructed using the same machinery invoked by the Specify command However it is known only to the enclosing Oxs_UniaxialAnisotropy object and no references to it are possible either from other Specify blocks or even elsewhere in side the same initialization string Because it cannot be referenced the object does not need an instance name It does need an initialization string however which is given here as the 4 tuple min norm 1 max_norm 1 Notice how the curly braces are nested so that this 4 tuple is presented to the Oxs_RandomVectorField initializer as a single item while Oxs_RandomVectorField and the associated initialization string are wrapped up in an other Tcl list so that the value associated with axis is parsed at that level as a single item The value associated with K1 is another embedded Oxs_Ext object In
357. y Max Angle deg 44 4 E Anisotropy Energy E Demag Energy E Zeeman Energy E Max Angle Overview The application mmDataTable provides a data display service to its client applications It accepts data from clients which are displayed in a tabular format in a top level window Its typical use is to display the evolving values of quantities computed by micromagnetic solver programs Launching mmDataTable may be started either by selecting the mmDataTable button on mm Launch or from the command line via tclsh oommf tcl mmDataTable standard options net lt 0 1 gt net lt 0 1 gt Disable or enable a server which allows the data displayed by mmDataTable to be updated by another application By default the server is enabled When the server is disabled mmProbEd is only useful if it is embedded in another application 126 Inputs The client application s that send data to mmDataTable for display control the flow of data The user interacting with the mmDataTable window controls how the data is displayed Upon launch mmDataTable displays only a menubar Upon user request a display window below the menubar displays data values Each message from a client contains a list of name value units triples containing data for display For example one element in the list might be Magnetization 800000 A m mmDataTable stores the latest value it receives for each name Earlier values are discarded when new data arrives from a
358. y can be shut down to save energy Or the operating system may move threads away from the memory node where they have allocated memory which effectively reduces memory bandwidth In such cases you might want to launch Boxsi with the numanodes auto option This overrides the operating systems preferences and ties threads to particular memory nodes for the lifetime of the process On Linux boxes you should also check the cpu frequency governor selection and settings If you want to run two instances of Boxsi concurrently you might launch each with the threads 4 option so that each job has four threads for the operating system to schedule If you don t like the default scheduling by the operating system you can use the numanodes option but what you don t want to do is launch two jobs with numanodes auto because the auto option assigns threads to memory nodes from a fixed sequence list so both jobs will be assigned to the same nodes Instead you should manually assign the nodes with a different set to each job For example you may launch the first job with numanodes 0 1 and the second job with numanodes 2 3 One point to keep in mind when assigning nodes is that some node pairs are closer with respect to memory latency and bandwidth than others For example memory node 0 and memory node 1 may be directly connected via a point to point link so that data can be transferred in a single hop But sending data from
359. y nodes These must be passed on the command line as a single parameter so either insure there are no spaces in the list or else protect the spaces with outlying quotes For example numanodes 2 4 6 or numanodes 2 4 6 Threads are assigned to the nodes in order in round robin fashion The user can ei ther assign all the system nodes to the Oxsii process or may restrict Oxsii to run on a subset of the nodes In this way the user may reserve specific processing cores for other processes or other instances of Oxsii Although it varies by system typically there are multiple processing cores associated with each memory node If the keyword auto is selected then the threads are assigned to a fixed node sequence that spans the entire list of memory nodes If the keyword none is selected then threads are not tied to nodes by Oxsii but are instead assigned by the operating system In this last case over time the operating system is free to move the threads among proces sors In the other two cases each thread is tied to a particular node for the lifetime of the Oxsii instance See also the discussion on threading considerations in the Boxsi documentation The default value for nodes is none which allows the operating system to assign and move threads based on overall system usage This is also the behavior obtained when the Oxs build is not NUMA aware On the other hand if a machine is dedicated primarily to running one insta
360. zes the host name localhost It may be necessary to edit a file which records that localhost is a synonym for the loop back interface 127 0 0 1 If a file named hosts exists in your system area for example C Windows hosts be sure it includes an entry mapping 127 0 0 1 to localhost If no hosts file exists but a hosts sam file exists make a copy of hosts sam with the name hosts and edit the copy to have the localhost entry The directory that holds the tclsh and wish programs also holds several d11 files that OOMME software needs to find to run properly Normally when the OOMMF bootstrap application Sec 5 or mmLaunch Sec 6 is used to launch OOMMF programs they take care of making sure the necessary d11 files can be found As an additional measure you might want to add the directory which holds the tclsh and wish programs to the list of directories stored in the PATH environment variable All the directories in the PATH are searched for d11 files needed when starting an executable 2 2 3 Compiling and Linking If you downloaded a distribution with pre compiled executables you may skip this section When building OOMMF software from source code be sure the C compiler reported by oommf tcl platform is properly configured In particular if you are running on a Win dows system please read carefully the notes in Advanced Installation Sec 2 4 2 pertaining to your compiler The compiling and linking of the C portions of O

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