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Data Presentation techniques (Mapping)

1. with gdal path to gdal config Build and install GDAL GRASS make sudo make install Check if GRASS is now supported by GDAL OGR gdalinfo formats ogrinfo formats Qt4 Qt 4 1 or higher is required in order to compile QGIS You may already have Qt on your system If so check to see if you have version 4 1 x or later You can check the Qt version using the find command find name qglobal h 2 gt dev null xargs grep QT_VERSION_STR If you have the locate utility installed you can do the same more quickly using locate qglobal h xargs grep QT_VERSION_STR In either case the result should look something like this QGIS 0 8 User Guide 101 define QT_VERSION_STR 4 1 0 In the example above Qt 4 1 0 is installed If Qt is not installed you will have to install the Qt development package for your distribution If you are not able to install the required Qt packages you will have to build from source To install Qt from source 1 Download Qt from http www trolltech com developer choose the Qt X11 Free Edition 2 Unpack the distribution 3 Follow directions provided in the distribution directory doc html install x11 html 4 Use whatever configure options you like but make sure you include thread for use with QGIS You can configure Qt with minimal options configure thread 5 Complete the installation per the instructions provided in the Qt documentation see step 3 F Building QGIS A
2. Type copyright for distribution terms h for help with SQL commands for help with psql commands g or terminate with semicolon to execute query q to quit gis_data CREATE INDEX sidx_alaska_lakes ON alaska_lakes gis_data USING GIST the_geom GIST_GEOMETRY_OPS CREATE INDEX gis_data VACUUM ANALYZE alaska_lakes VACUUM gis_data q gsherman madison current 4 3 The Vector Properties Dialog The vector properties dialog provides information about a layer symbology settings and labeling options If your vector layer has been loaded from a PostgreSQL PostGIS datastore you can also alter the underlying SQL for the layer either by hand editing the SQL on the General tab or by invoking the query builder dialog on the General tab To access the properties dialog double click on a layer in the legend or right click on the layer and select Properties from the popup menu 4 3 1 Vector Symbology QGIS supports a number of symbology renderers to control how vector features are displayed Currently the following renderers are available Single symbol a single style is applied to every object in the layer QGIS 0 8 User Guide 25 4 3 The Vector Properties Dialog Graduated symbol objects within the layer are displayed with different symbols classified by the values of a particular field Continuous colour objects within the layer are displayed with a spread of colours classified by the numerical values withi
3. Figure 11 Dialog for adding a WMS server showing its available layers G Add Layer s from a Server ss y mak l Server Connections NASA Onearth Connect Image encoding PNG JPEG Name Tite a dail y_aqua Daily composite of MODIS AQUA images BMNG Blue Marble Next Generation Global MODIS derived image modis Blue Marble Global MODIS derived image F default visual huemapped_srtm SRTM derived global elevation 3 arc second hue mapped srtmplus Global 1km elevation seamless SRTM tand elevation and fa workwind_dem SRTM derived global elevation 3 arc second tz Coordinate Reference System 2 avaiable WGS 64 Help Not connected Tip 22 WMS LAYER ORDERING In this version of QGIS WMS layers rendered by a server are overlaid in the order listed in the Layers section from top to bottom of the list If you want to overlay layers in the opposite order then you can select Add WMS layer a second time choose the same server again and select the second group of layers that you want to overlay the first group Transparency In this version of QGIS the transparency setting is hard coded to be always on where available Therefore no option for it exists on screen This in theory allows you to overlay WMS layers on other layers raster vector or WMS and still see through to those lower layers Tip 23 WMS LAYER TRANSP
4. THE REGIONAL TRAINING WORKSHOP ON LARVAL FISH IDENTIFICATION AND FISH EARLY LIFE HISTORY SCIENCE SEAFDEC TD SAMUT PRAKAN THAILAND 16 31 MAY 2007 TRD 05 Data Presentation techniques Mapping Quantum GIS User Guide Quantum GIS User Guide Version 0 8 TITAN Gary E Sherman Tim Sutton Radim Blazek Stephan Holl Otto Dassau Tyler Mitchell Brendan Morely Lars Luthman Contents Contents 3 4 1 Menu Ba 4 4 Map Vie 3 9 Spatial Bookmark 3 9 1 Creating a Bookmark QGIS 0 8 User Guide ii Contents Improving Perform y 24 4 3 The Vector Properties Dia 25 4 3 1 Vector Symboloay 25 4 4 1 Defining Action 27 44 2 ing Actions 28 ogra A 41 QGIS 0 8 User Guide jii Contents 42 8 oadinag Ata 53 8 3 Vector Data Mode 53 8 4 1 Toolba 54 QGIS 0 8 User Guide iv Contents O ALG O A 10 2 6 Uploading GPS data to a device 10 2 7 Defining new device types A 2 GDAL Raster Format C 1 Installing GNU Linux Version D Getting QGIS D 1 Binary packages 0 00004 ee ee QGIS 0 8 User Guide E 6 GDAL OGR E 8 qdal GRASS plugins F Building QGI E 2 2 GDAL OGR F 2 3 PostagreSQ d QGIS 0 8 User Guide E4 PostGIY iv he eee aa E5 SOLON 22 2 6 462 od eB Rw g EZ ARO o o eee 8 eB Abe Gd Fi Quick and Dirty 2 SET ee E2 4 GRASS F2 5 pythonl F 2 6
5. feature vertex B2 editing 28 vertex B1 ESRI shapefiles 18 MapInfo 20 moving vertex paste feature PostGIS see PostGIS properties dialog 25 renderers continuous color 26 graduated symbol 26 single symbol 25 unique value symbology 25 transparency 26 WKT 49 WMS capabilites 46 client 42 about 42 connection parameters 43 layers 44 109 Index limits 47 coordinate reference system 45 CRS 45 identify 46 image encoding 44 layer settings editing 48 layer transparency metadata 46 properties 46 remote server authentication 48 layer ordering 45 selection 43 URL 43 URL 43 zoom mouse wheel 11 QGIS 0 8 User Guide 110
6. usr local qgis with gdal usr local gdal bin gdal config with postgresql usr local psql bin pg_config with geos usr local bin geos config with sqlite3dir usr local with grass usr local grass 6 0 3 with python This will configure QGIS to use GDAL GRASS and PostgreSQL Additionally it should be built against QT4 living in usr share qt4 QGIS will be installed in usr local qgis If gdal config and pg_config are both in the PATH there is no need to use the with gdal and with postgresql options The configure script will properly detect and configure GDAL and PostgreSQL QGIS 0 8 User Guide 104 You must still use the with grass option if building with GRASS support To enable the python bindings supply the option with python as well F 2 7 Compiling and Installing QGIS Once properly configured simply issue the following commands make sudo make install Note You must do a sudo make install and start QGIS from the installed location In case of the example above the QGIS binary resides in the bin subdirectory of the directory specified with the prefix option usr local qgis bin For information on using QGIS see the QGIS User Guide G Building Plugins The QGIS source distribution contains a number of core plugins These are built along with QGIS using the instructions above Additional external plugins are available from the QGIS SVN repository at http svn qgis org WebSVN Ins
7. Aspect _ Te OUO O Scale 1 42875 600864 4920298 x Render Note Your window decorations title bar etc may appear different depending on your operating system and window manager The QGIS GUI is divided into six areas 1 Menu bar 2 Tool bar 3 Map legend QGIS 0 8 User Guide 8 3 4 QGIS GUI 4 Map view 5 Map overview 6 Status bar These six components of the QGIS interface are described in more detail in the following sections 3 4 1 Menu Bar The menu bar provides access to various QGIS features using a standard hierarchical menu The top level menus and a summary of some of the functions provided are e File New Project see Section 8 7 Open Project see Section 3 7 Open Recent Projects see Section B 7 Save Project see Section 3 7 Save Project As see Section B 7 Save as Image Export to MapServer Map Print Exit e View Zoom Full Zoom To Selection Zoom To Layer Zoom Last Refresh Show Bookmarks New Bookmark e Layer Add a Vector Layer see Section 4 Add a Raster Layer see Section QGIS 0 8 User Guide 9 3 4 QGIS GUI Add a PostGIS Layer see Section 4 2 Add a WMS Layer see Section 6 2 Remove Layer New Vector Layer In Overview Add All To Overview Remove All From Overview Hide All Layers Show All Layers e Settings Proje
8. Delimited Text dialog as shown in Figure 24 First select the file to import by clicking on the ellipsis button Select the desired text file from the file dialog Once the file is selected the plugin attempts to parse the file using the last used delimiter in this case Figure B5 In this case the delimiter is not correct for the file The file is actually tab delimited Note that the X and Y field drop down boxes do not contain valid field names To properly parse the file change the delimiter to tab using t this is a regular expression for the tab character After changing the delimiter click Parse The drop down boxes now contain the fields properly parsed as shown in Figure 26 Choose the X and Y fields from the drop down boxes and enter a Layer name as shown in Figure 27 To add the layer to the map click Add Layer The delimited text file now behaves as any other map layer in QGIS Figure 28 QGIS 0 8 User Guide 76 10 3 Using the Delimited Text Plugin Figure 24 Delimited Text Dialog Greate a Layer from a Delimited Text File be Wt Ge Tom fete ew Sim je 2 FEES ESTERS Delimited Text Layer Description Select the file containing delimited text with latlon coordinates that you would like to use as a point layer and this plugin will do the job for you Use the layer name box to specify the legend name for the new layer Use the delimeter box to specify what the delimeter is for your
9. Example Use of Configure Contents 95 vi List of Figures List of Figures 1 _ Main window with spearfish sample data 8 14 GRASS Edit Dialog 55 6 eld 2 O 3 78 27 Selecting the X and Y Fields 28 Delimited Text Layer Added to QGIS 79 QGIS 0 8 User Guide vii List of Tables List of Tables ee ere en ee ree reer ee 22 2 WM onnection Parameters 2 ee 43 _ Example Public WMS URLS 2 2 2 0 0 a 44 4 RASS Digitizing Tools sea aaa a a a a a a ae R 56 QGIS Core Pluging s sa saasaa na aoa wna a a a a a a e a 68 viii QGIS 0 8 User Guide 1 Forward Welcome to the wonderful world of Geographical Information Systems GIS Quantum GIS QGIS is an Open Source Geographic Information System The project was born in May of 2002 and was established as a project on SourceForge in June of the same year We ve worked hard to make GIS software which is traditionaly expensive commerical software a viable prospect for anyone with basic access to a Personal Computer QGIS currently runs on most Unix platforms Windows and OS X QGIS is developed using the Qt toolkit and C This means that QGIS feels snappy to use and has a pleasing easy to use graphical user interface QGIS aims to be an easy to use GIS providing common functions and features The initial goal was to provide a GIS data viewer QGIS has reached that point in its evolution and is being used by many for their daily GIS
10. GPS device the port that it is connected to the feature type that you want to download the GPX file where the data should be stored and the name of the new layer The device type you select in the GPS device menu determines how GPSBabel tries to communicate with the device If none of the device types works with your GPS device you can create a new type see section 10 2 7 The port is a file name or some other name that your operating system uses as a reference to the physical port in your computer that the GPS device is connected to On Linux this is something like dev ttySO or dev ttyS1 and on Windows it s COM1 or COM2 When you click OK the data will be downloaded from the device and appear as a layer in QGIS QGIS 0 8 User Guide 71 10 2 Using the GPS Plugin Figure 21 File selection dialog for the import tool Select file and format to import CoFilot Fight Planner DNA Delorme GPS Log Delorme Routes EasyGPS Binary Format Fugawi GPS Drive GPS Util GPSman 10 2 6 Uploading GPS data to a device You can also upload data directly from a vector layer in QGIS to a GPS device using the tool Upload to GPS The layer must be a GPX layer To do this you simply select the layer that you want to upload the type of your GPS device and the port that it s connected to Just as with the download tool you can specify new device types if your
11. GeoTIFF tif e Hierarchical Data Format Release 4 HDF4 e Erdas Imagine img 4GRASS raster support is supplied by the QGIS GRASS data provider plugin QGIS 0 8 User Guide 84 A 2 GDAL Raster Formats e Atlantis MFF2e e Japanese DEM mem e JPEG JFIF jpg e JPEG2000 jp2 j2k e JPEG2000 jp2 j2k e NOAA Polar Orbiter Level 1b Data Set AVHRR e Erdas 7 x LAN and GIS e In Memory Raster e Atlantis MFF e Multi resolution Seamless Image Database MrSID e NITF e NetCDF e OGDI Bridge e PCI aux Labelled e PCI Geomatics Database File e Portable Network Graphics png e Netpbm ppm pgm e USGS SDTS DEM CATD DDF e SAR CEOS e USGS ASCII DEM dem e X11 Pixmap xpm QGIS 0 8 User Guide 85 B GNU Public License GNU GENERAL PUBLIC LICENSE Version 2 June 1991 Copyright C 1989 1991 Free Software Foundation Inc 59 Temple Place Suite 330 Boston MA 02111 1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document but changing it is not allowed Preamble The licenses for most software are designed to take away your freedom to share and change it By contrast the GNU General Public License is intended to guarantee your freedom to share and change free software to make sure the software is free for all its users This General Public License applies to most of the Free Software Foundation s software and to any other program whose authors commit
12. QGIS Currently the external plugins are only available directly from SVN To check out all available external plugins do the following svn co https svn qgis org repos qgis trunk external_plugins external_qgis_plugins This will create a folder external_qgis_plugins in your current folder Each subdirectory has its own compile and install instructions Read them carefully in order to build the plugin QGIS 0 8 User Guide 68 10 1 An Introduction to Using Plugins 10 1 6 Plugin templates If you like to develop your own QGIS plugin the main sources include a nice script which guides you through the process of creating your own template directory structure within the QGIS source tree The script lives in QGIS src plugins plugin_builder pl The only thing to do is coding your functions into the plugin and of course contribute your plugin the the QGIS development team Beside that the QGIS wiki and the QGIS blog provide useful articles about writing your own plugin as well Check the websites for details QGIS 0 8 User Guide 69 10 2 Using the GPS Plugin 10 2 Using the GPS Plugin 10 2 1 What is GPS GPS the Global Positioning System is a satellite based system that allows anyone with a GPS receiver to find their exact position anywhere in the world It is used as an aid in navigation for example in airplanes in boats and by hikers The GPS receiver uses the signals from the satellites to calculate its latitude longitude
13. a connection are shown in Table Once the parameters have been filled in you can test the connection by clicking on the Test Connection button To save the password with the connection information check the Save Password option QGIS 0 8 User Guide 21 4 2 PostGIS Layers Table 1 PostGIS Connection Parameters A name for this connection Can be the same as Database Host Name of the database host This must be a resolvable host name the same as would be used to open a telnet connection or ping the host Name of the database Port number the PostgreSQL database server listens on The default port is 5432 User name used to login to the database password used with Username to connect to the database Tip 5 QGIS USER SETTINGS AND SECURITY Your customized settings for QGIS are stored based on the operating system On Linux Unix the settings are stored in your home directory in qt qgisrc On Windows the settings are stored in the registry Depending on your computing environment storing passwords in your QGIS settings may be a security risk 4 2 2 Loading a PostGIS Layer wl Once you have one or more connections defined you can load layers from the PostgreSQL database Of course this requires having data in PostgreSQL See Section for a discussion on importing data into the database To load a layer from PostGIS perform the following steps e f the PostGIS layer dialog is not already open click on the Add a PostGIS Laye
14. a GRASS session Then your current mapset will be opened for writing Another option for opening a mapset for writing is provided through the GRASS plugin entry Use Plugins gt GRASS gt Open mapset If you have a greyed out GRASS toolbox button make sure you open a valid mapset for writing since the GRASS plugin needs a mapset to store its results The toolbox also provides a very useful data browser for browsing through your current location and its containing mapsets 8 6 1 Modules inside the toolbox The GRASS toolbox provide a collection of GRASS modules which can be used from within QGIS They are grouped to thematic blocks which can be defined by yourself see section 8 6 3 QGIS 0 8 User Guide 57 8 6 GRASS Toolbox When clicking on a module a new tab will be added to your toolbox which provides three new sub tabs 1 Options 2 Output 3 Manual Options This tab provides you with a very simplified entry field where you need to select the needed maps and enter parameters to run the selected module Note that this options are kept as simple as possible in order to keep the structure clear If you need more option of the module feel free to use the GRASS shell to run the module Output This tab provides you with the output generated from the running module After you hit the run button the module switches to the Output tab and you will see information about the process If all goes well you will see Succe
15. address or host name of the proxy server you would use to access this WMS server or leave blank if no proxy is needed Proxy Port Port number of the proxy server User name used to login to the proxy server Proxy Password Password used to login to the proxy server At least Name and URL are required entries the proxy entries can be left blank if you have a clear path to your WMS server Once the new WMS Server has been created it will be preserved across future QGIS sessions Tip 20 ON WMS SERVER URLS Be sure when entering in the WMS server URL that you have the base URL For example you shouldn t have fragments such as request GetCapabilities or version 1 0 0in your URL Table 8 shows some example WMS URLs to get you started These links were last checked in QGIS 0 8 User Guide 43 6 2 WMS Client December 2006 but could change at any time Table 3 Example Public WMS URLs Atlas of Canada http atlas gc ca cgi bin atlaswms_en DEMIS http www2 demis nl wms wms asp wms WorldMap amp htto www ga gov au bin getmap pl dataset national NASA JPL OnEarth http wms jpl nasa gov wms cgi QGIS Users http qgis org cgi bin mapserv map var www maps main map amp An exhaustive list of WMS servers can be found at http wms sites com 6 2 3 Loading WMS Layers Once you have successfully filled in your parameters you can select the Connect button to retrieve the capabilities of the selected server This incl
16. and sometimes elevation Most receivers also have the capability to store locations known as waypoints sequences of locations that make up a planned route and a tracklog or track of the receivers movement over time Waypoints routes and tracks are the three basic feature types in GPS data QGIS displays waypoints in point layers while routes and tracks are displayed in linestring layers 10 2 2 Loading GPS data from a file There are dozens of different file formats for storing GPS data The format that QGIS uses is called GPX GPS eXchange format which is a standard interchange format that can contain any number of waypoints routes and tracks in the same file gt To load a GPX file you need to use the GPS Tools plugin When this plugin is loaded a button with a small handheld GPS device will show up in the toolbar the device looks a bit like a mobile phone Clicking on this button will open the GPS Tools dialog see figure 20 Figure 20 The GPS Tools dialog window GPS Tools e ipon other file Download from GPS Upload to GPS Description GPX is the GPS eXchange file format which is used to store information about waypoints routes and tracks Select a GPX file and then select the feature types that you want to load QGIS 0 8 User Guide 70 10 2 Using the GPS Plugin Use the browse button to select the GPX file then use the checkboxes to select the feature types you want to load fro
17. and PostGIS identifiers are present in the database and can be used to specify a projection in QGIS In order to use OTF projection your data must contain information about its coordinate system For PostGIS layers QGIS uses the spatial reference identifier that was specified when the layer was created For data supported by OGR QGIS relies on the presence of a format specific means of specifying the coordinate system In the case of shapefiles this means a file containing the Well Known Text WKT specification of the the coordinate system The projection file has the same base name as the shapefile and a prj extension For example a shapefile named lakes shp would have a corresponding projection file named lakes prj 7 2 Getting Started At startup QGIS does not have OTF projection enabled To use OTF projection you must open the Project Properties dialog select a projection for the map and enable projections There are two ways to open the Project Properties dialog 1 Select Project Properties from the Settings menu 2 Click on the projector icon in the lower right hand corner of the statusbar Tip 25 PROJECT PROPERTIES DIALOG If you open the Project Properties dialog from the Settings menu you must click on the Projection tab to view the projection settings Opening the dialog from the projector icon will automatically bring the Projection tab to the front QGIS 0 8 User Guide 49 7 2 Getting Started The Projection dialog
18. connected without gaps An area is identified labeled by the centroid of the area Besides boundaries and centroids a vector map can also contain points and lines All these geometry elements can be mixed in one vector and will be represented in different so called layers inside QGIS It is possible to store more layers in one vector dataset For example fields forests and lakes can be stored in one vector Adjacent forest and lake can share the same boundary but they have separate attribute tables It is also possible to attach attributes to boundaries For example the boundary between lake and forest is a road so it can have a different attribute table The layer of the feature is defined by layer inside GRASS Layer is the number which defines if there are more than one layer inside the dataset e g if the geometry is forest or lake For now it can be only a number in the future GRASS will also support names as fields in the user interface Attributes can be stored in external database tables for example DBF PostgreSQL MySQL SQLITES etc Attributes in database tables are linked to geometry elements using category Category key ID is an integer attached to geometry primitives and it is used as the link to one column in the database table Tip 27 LEARNING THE GRASS VECTOR MODEL The best way to learn the GRASS vector model and its capabilities is to download one of the many GRASS Tu
19. data viewing needs QGIS supports a number of raster and vector data formats with new support easily added using the plugin architecture see Appendix Alfor a full list of currenly supported data formats QGIS is released under the GNU Public License GPL Developing QGIS under this license means that you can inspect and modify the source code and guarantees that you our happy user will always have access to a GIS program that is free of cost and can be freely modified You should have received a full copy of the license with your copy of QGIS and is also available as Appendix B Note The latest version of this document can always be found at http qgis org docs userguide pdf 1 1 Major Features QGIS has many common GIS features and functions The major features are listed below 1 Support for spatially enabled PostgreSQL tables using PostGIS 2 Support for ESRI shapefiles and other vector formats support by the OGR library including MapInfo files 3 GRASS integration including view edit and analysis 4 On the fly projection of vector layers 5 Map composer 6 Identify features 7 Display attribute table 8 Select features QGIS 0 8 User Guide 1 10 11 12 13 14 15 16 17 18 19 20 1 2 Whats New in 0 8 Label features Persistent selections Save and restore projects Support for raster formats supported by the GDAL library Change vector symbology single graduated unique value and contin
20. device isn t in the list This tool is very useful together with the vector editing capabilities of QGIS You can load a map create some waypoints and routes and then upload them and use them in your GPS device 10 2 7 Defining new device types There are lots of different types of GPS devices The QGIS developers can t test all of them so if you have one that does not work with any of the device types listed in the download and upload tools you can define your own device type for it You do this by using the GPS device editor which you start by clicking the Edit devices button in the download or the upload window QGIS 0 8 User Guide 72 10 2 Using the GPS Plugin Figure 22 The download tool GPS Tools xX Upload to GPS Description This tool will halp you download data from a GPS device Choose your GPS device the poart it is connected to the feature type you want to download a name for your new layer and the GPX file where you want to store the data If your device iat listed or if you vant to change some settings you can also edit the devices This tool uses the progam GPS Babel http qnehabel_sf net to transfer the cata If you dont have GPS Babel installed where OGIS can find it this tool will not work ida w e Edt cevioss Feature type Waypoints x Output file an Layer mame To define a new device you simply click the New device button enter a name a download command and
21. file e g space commar or tab Le Note this box accepts regex entries so use t for tab and 5 ennn harnhancinn a dalimatar_nrace tha narea Delimited textfile B Layer name Delimiter A X field v Y field y Help Parse Add Layer Close Figure 25 File Selected Greate a Layer fiom a Delimited Text File Be ER Go pow Setrus few ge Goo ones QGIS 0 8 User Guide leva rtiel Jatir LY Ss nas tama Delimited Text Layer Description Select the file containing delimited text with latlon coordinates that you would like to use as a point layer and this plugin will do the job for you Use the layer name box to specify the legend name for the new layer Use the delimeter box to specify FE what the delimeter is for your file e g space commar gt Delimited text file gnis_no_east_hemi_tabbed txt Oe Layer name Delimiter T idee longdec celi 7 py dec tongdec cel 7 field ttdec longdec cell x aai ttdec longdec cell Help Parse Add Layer Close 77 10 3 Using the Delimited Text Plugin Figure 26 Fields Parsed from Text File Greate a Layer from a Delimited TextFile eee ee kee B Delimited Text Layer ea s Lowy Description Select the file containing delimited text with lat lon coordinates that you would like to use as a point layer and this plugin will do the job for you Use the layer name box to specify the legend n
22. file uses as delimiter Any character can be used to delimit the fields 2 The first row is the header row It contains the fields name latdec longdec and cell 3 No quotes are used to delimit text fields 4 The x coordinates are contained in the ongdec field 5 The y coordinates are contained in the atdec field QGIS 0 8 User Guide 75 10 3 Using the Delimited Text Plugin 10 3 2 Using the Plugin To use the plugin you must have QGIS running and use the Plugin Manager to load the plugin Start QGIS then Open the Plugin Manager by choosing the Too s Plugin Manager menu The Plugin Manager displays a list of available plugins Plugins that are already loaded have a check mark to the left of their name Click on the checkbox to the left of the Add Delimited Text Layer plugin and click Ok to load it as shown in Figure 23 Figure 23 Plugin Manager Dialog QGIS Plugin Manger Plugin Directory homeigshermaniqgis02 libiqgis e To load a plugin click the checkbox next to the plugin and click Ok Name Version Description za Add Delimited Text Layer 0 1 This plugin provides support for delimited text files containing x y coor 4 PostgresSQL Geoprocessing Version 0 1 Geoprocessing functions for working with Postgre SQL PostGIS layers o SPIT Version 0 1 Shapefile to Postgre SQL PostGIS Import Tool g ele Ok Close A new toolbar icon is now present a Click on the icon to open the
23. installation D 1 Binary packages Binary packages mosily inofficial are provided under following urls SuSE e GDF Hannover http www gdf hannover de software Mandriva Mandrake e Mandrivaclub http rpms mandrivaclub com search php query qgisxsubmit Search e GDF Hannover http www gdf hannover de software Fedora redhat e Intevation GmbH http ftp gwdg de pub misc freegis intevation freegis fedora e MPA http mpa itc it markus grass61 fc4 e Mappinghacks http www mappinghacks com rpm fedora 3 Debian e DebianGIS Project http pkg grass alioth debian org cgi bin wiki pl e Bullhorn org http bullhorn org debian qgis MS Windows e Sourceforge http prdownloads sourceforge net qgis QGIS 0 8 User Guide 94 Mac OSX e Sourceforge http rpms mandrivaclub com search php query qgis amp submit Searcht Various plattforms via BitTorrent e MRCC BitTorrent http gisalaska com torrents E Dependencies The following dependencies need to be install prior QGIS installation The order given here should be used because some programs depend on each other Basically this order is needed e PROJ 4 e GEOS e PostgreSQL e PostGIS e SQLite3 e GDAL OGR e GRASS e GDAL GRASS e QT4 e QGIS Optionaly you need python in order to get the new UMN MapServer exporter compiled E 1 Proj 4 Proj 4 provides the functions needed for on the fly projection of map layers starting fr
24. location Setting the QTDIR environment variable will make ensure that the detection succeeds You can also specify the path using the with qtdir option F 2 2 GDAL OGR If the gdal config script is in the PATH configure will automatically detect and configure GDAL support If not in the path you can specify the full path to gdal config using the with gdal option For example configure with gdal usr mystuff bin gdal config F 2 3 PostgreSQL If the pg_config script is in the PATH configure will automatically detect and configure PostgreSQL support If not you can use the with postgresql option to specify the full path to pg_config For example QGIS 0 8 User Guide 103 F 2 Configuring QGIS the right way configure with postgresql usr local psql bin pg_config F 2 4 GRASS To build QGIS with GRASS support you must specify the full path to the installed GRASS binary package configure with grass usr local grass 6 0 3 This assumes that GRASS is installed in the default location Change the path to match the location of your GRASS installation F 2 5 python In order to build QGIS with the new UMN MapServer mapfile exporter you need to configure python witzhin QGIS Therefor you need to give the following parameter configure with python F 2 6 Example Use of Configure An example of use of configure for building QGIS with all options configure with qtdir usr share qt4 prefix
25. open the corresponding attribute table and choose the Advanced button This starts the Query Builder and allows to define a subset of a table and display it as described in Section 6 The second option to start the Query Builder as decribed in Section is currently not supported for OGR and GRASS layers QGIS 0 8 User Guide 35 5 Working with Raster Data QGIS supports a number of raster data formats This section describes how to work with raster data in QGIS 5 1 What is raster data Raster data in GIS are matrices of discrete cells that represent features on above or below the earth s surface Each cell in the raster grid is the same size and cells are usually rectangular in QGIS they will always be rectangular Typical raster datasets include remote sensing data such as aerial photography or satellite imagery and modelled data such as an elevation matrix Unlike vector data raster data typically do not have an associated database record for each cell In GIS a raster layer would have georeferencing data associated with it which will allow it to be positioned correctly in the map display to allow other vector and raster data to be overlaid with it QGIS makes use of georeferenced rasters to properly display the data 5 2 Raster formats supported in QGIS QGIS supports a number of different raster formats Currently tested formats include e Arc Info Binary Grid e Arc Info ASCII Grid e GRASS Raster e GeoTlIFF e
26. registered automatically by QGIS at startup They are not managed by the Plugin Manager but are used behind the scenes when a corresponding data type is added as a layer in QGIS 10 1 4 Core Plugins QGIS currently contains 9 core plugins that can be loaded using the Plugin Manager Table b lists each of the core plugins along with a description of their purpose and the toolbar icon Note the GRASS plugin is not included below because it installs its own toolbar see section 8 for a discussion of available features in the GRASS plugin QGIS 0 8 User Guide 67 10 1 An Introduction to Using Plugins Table 5 QGIS Core Plugins eon Plugin Desmi O O OOS PostgreSQL Geoprocessing Buffer a PostGIS layer SPIT Shapefile to PostGIS Import Tool import shapefiles into PostgreSQL Georeferencer Georeferencing rasterlayers The georeferencer plugin is only available if you have installed the gsl libraries and headers during compile time Please check the installation chapter C for details Cy North Arrow Add a north arrow to the map canvas Tip 32 PLUGINS SETTINGS SAVED TO PROJECT When you save a qgs project any changes you have made to NorthArrow ScaleBar and Copyright plugins will be saved in the project and restored next time you load the project 10 1 5 External Plugins QGIS also comes with some externally developed plugins They are not shipped with the default distribution However they can be compiled and used within
27. the maps in view reflect changes you make in the legend area Tip 3 ZOOMING THE MAP WITH THE MOUSE WHEEL You can use the mouse wheel to zoom in and out on the map Place the mouse cursor inside the map area and roll it forward away from you to zoom in and backwards towards you to zoom out The mouse cursor is the center where the zoom occurs You can customize the behavior of the mouse wheel zoom using the Map tools tab under the Settings Options menu 3 4 5 Map Overview The map overview area provides a full extent view of layers added to it Within the view is a rectangle showing the current map extent This allows you to quickly determine which area of the map you are currently viewing Note that labels are not rendered to the map overview even if the layers in the map QGIS 0 8 User Guide 11 3 5 Rendering overview have been set up for labeling You can add a single layer to the overview by right clicking on it in the legend and choosing Add to overview You can also add or remove all layers to the overview using the Overview tools on the toolbar You can also grab the red rectangle showing your current extent and pan around the map view will update accordingly 3 4 6 Status Bar The status bar shows you your current position in map coordinates e g meters or decimal degrees as the mouse pointer is moved across the map view The status bar also shows the view extents of the map view as you pan and zoom in and out A progress ba
28. the search feature to find it Enter the identifier and click on Find 7 2 1 Specifying a Projection QGIS automatically sets the map projection to the coordinate system of the first layer loaded One way to specify the map projection is to first load a layer with the projection you want for the entire map Then open the Project Properties dialog and click on the Enable on the fly projection checkbox You can now close the Project Properties dialog and add additional layers to the map If you have already added layers and want to enable OTF projection open the Project Properties dialog and find the projection or geographic coordinate system you want to use in the list of projections Alternatively you can use the search feature as described in the previous section 7 3 Custom Projections If QGIS doesn t have the projection you need you can define a custom projection To define a projection select Custom Projections from the Settings menu Custom projections are stored in your QGIS user database In addition to your projections this database contains your spatial bookmarks and other custom data Figure 13 Custom Projection Dialog OS X e09 Y Custom Projection Definition Define Test Custom Projection Definition You can define your own custom projection here The definition must conform to the proj4 format for specifying a Spatial Reference System Name albers test Parameters proj aea lat_1 55 lat_2 65 lat_
29. update the display as QGIS 0 8 User Guide 13 3 6 Measuring features are read from the datastore choose Preferences from the Settings menu and click on the Rendering tab Set the feature count to an appropriate value to update the display during rendering Setting a value of 0 disables update during drawing this is the default Setting a value too low will result in poor performance as the map canvas is continually updated during the reading of the features A suggested value to start with is 500 NOTE This feature is currently disabled because it does not works as expected under Qt 4 2 3 6 Measuring 3 6 1 Measure length Lu QGIS is also able to measure distances between given points This tool allows you to click points on the map Each segment length shows up in the measure window and additionaly the total length is printed To stop measuring click your right mouse button 3 6 2 Measure areas p Also areas can be measured The window only shows the accumulated area size in the measure window see figure 2 Figure 2 Measure tools in action Measure Measure a Measure lines b Measure areas QGIS 0 8 User Guide ag 3 7 Projects 3 7 Projects The state of your QGIS session is considered a Project QGIS works on one project at a time Settings are either considered as being per project or as a default for new projects see Section B 8 QGIS can save the state of your workspace into a project file usi
30. 0 50 lon_0 154 x_0 0 y_0 0 ellps clrk66 datum NAD27 lofl gt gt New Save Delte Close QGIS 0 8 User Guide 51 7 3 Custom Projections At version 0 8 of QGIS defining a custom projection requires a good understanding of the Proj 4 projection library To begin refer to Cartographic Projection Procedures for the UNIX Environment A User s Manual by Gerald Evenden U S Geological Survey Open File Report 90 284 1990 available at ftp ftp remotesensing org proj 0F90 284 pdf This manual describes the use of the proj and related command line utilities The cartographic parameters used with proj and described in the user manual are the same as those used by QGIS The Custom Projections dialog requires only two parameters to define a user projection 1 a descriptive name and 2 the cartographic parameters To create a new projection click the New button and enter a descriptive name and the projection parameters Figure 13 shows the dialog with an example projection The parameters shown were entered based on a knowledge of the projection and the information found in OF 90 284 You can test your projection parameters to see if they give sane results by clicking on the Test tab and pasting your projection parameters into the Parameters field Then enter known WGS 84 latitude and longitude values in North and East fields respectively Click on Calculate and compare the results with the known values in you
31. 8 User Guide 42 6 2 WMS Client rasterizes the map and sends it back to the client in a raster format For QGIS this would typically be JPEG or PNG WMS is generically a REST Representational State Transfer service rather than a fully blown Web Service As such you can actually take the URLs generated by QGIS and use them in a web browser to retrieve the same images that QGIS uses internally This can be useful when troubleshooting problems as there are several brands of WMS servers in the market and they all have their own interpretation of the WMS standard WMS layers can be added quite simply as long as you know the URL to access the WMS server you have a serviceable connection to that server and the server understands HTTP as the data transport mechanism 6 2 2 Selecting WMS Servers You can begin by clicking the Add WMS layer button inside the toolbar or through the Layer menu The dialog for adding layers from the WMS server pops up In the Server Connections section select New Then enter in the parameters to connect to your desired WMS server as listed in table 2 Table 2 WMS Connection Parameters A name for this connection This name will be used in the Server Connections drop down box so that you can distinguish it from other WMS Servers URL URL of the server providing the data This must be a resolvable host name the same format as you would use to open a telnet connection or ping a host Proxy Host Network
32. ARENCY The availability of WMS image transparency depends on the image encoding used PNG and GIF support transparency whilst JPEG leaves it unsupported Coordinate Reference System A Coordinate Reference System is the OGC terminology for a QGIS Projection QGIS 0 8 User Guide 45 6 2 WMS Client Each WMS Layer can be presented in multiple CRSs depending on the capability of the WMS server You may notice that the x changes in the Coordinate Reference System x available header as you select and deselect layers from the Layers section To choose a CRS select Change and a screen similar to Figure 2 in Section Z 2 will appear The main difference with the WMS version of the screen is that only those CRSs supported by the WMS Server will be shown Tip 24 WMS PROJECTIONS For best results make the WMS layer the first layer you add in the project This allows the project projection to inherit the CRS you used to render the WMS layer On the fly projection see Section Z 2 1 can then be used to fit any subsequent vector layers to the project projection In this version of QGIS If you add a WMS layer later and give it a different CRS to the current project projection unpredictable results can occur 6 2 4 Using the Identify Tool Once you have added a WMS server and if any any layer from a WMS server is queryable you can then use the dentify tool to select a pixel on the map canvas A query is made to the WMS server for each s
33. ATASETS FROM PosTGIS Like the import tool shp2pgsql there is also a tool to export PostGIS datasets into shapefiles pgsql2shp This is shipped within your PostGIS distribution QGIS 0 8 User Guide 23 4 2 PostGIS Layers SPIT Plugin re QGIS comes with a plugin named SPIT Shapefile to PostGIS Import Tool SPIT can be used to load multiple shapefiles at one time and includes support for schemas To use SPIT open the Plugin Manager from the Tools menu and load the plugin by checking the box next to the SPIT plugin and click Ok The SPIT icon will be added to the plugin toolbar To import a shapefile click on the SPIT tool in the toolbar to open the dialog You can add one or more files to the queue by clicking on the Add button To process the files click on the Import button The progress of the import as well as any errors warnings will be displayed as each shapefile is processed Tip 8 IMPORTING SHAPEFILES CONTAINING POSTGRESQL RESERVED WORDS If a shapefile is added to the queue containing fields that are reserved words in the PostgreSQL database a dialog will popup showing the status of each field You can edit the field names prior to import and change any that are reserved words or change any other field names as desired Attempting to import a shapefile with reserved words as field names will likely fail ogr2ogr Beside sho2pgsq and SPIT there is another tool for feeding geodata in PostGIS ogr2ogr This is part of your GDAL ins
34. D FEATURES If your source and destination layers use the same projection then the pasted features will have geometry identical to the source layer However if the destination layer is a different projection then QGIS cannot guarantee the geometry is identical This is simply because there are small rounding off errors involved when converting between projections Deleting Selected Features To delete a feature select it using the selection tool and choose Delete selection from the editing tools Tip 17 FEATURE DELETION SUPPORT When editing ESRI shapefiles the deletion of features only works if QGIS is linked to a GDAL version 1 3 2 or greater The OS X and Windows versions of QGIS available from the download site are built using GDAL 1 3 2 or higher QGIS 0 8 User Guide 32 4 5 Editing Snap Mode QGIS allows digitised vertices to be snapped to other vertices of the same layer To set the snapping tolerance go to Settings gt Project Properties gt General gt Snapping Tolerance Note that the snapping tolerance is in map units Saving Edited Layers When a layer is in editing mode any changes remain in the memory of QGIS Therefore they are not committed saved immediately to the data source or disk When you turn editing mode off or quit QGIS for that matter you are then asked if you want to save your changes or discard them If the changes cannot be saved e g disk full or the attributes have values that are out of range
35. NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU SHOULD THE PROGRAM PROVE DEFECTIVE YOU ASSUME THE COST OF ALL NECESSARY SERVICING REPAIR OR CORRECTION QGIS 0 8 User Guide 89 12 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER OR ANY OTHER PARTY WHO MAY MODIFY AND OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE BE LIABLE TO YOU FOR DAMAGES INCLUDING ANY GENERAL SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES QGIS 0 8 User Guide 90 B 1 Quantum GIS Qt exception for GPL B 1 Quantum GIS Qt exception for GPL In addition as a special exception the QGIS Development Team gives permission to link the code of this program with the Qt library including but not limited to the following versions both free and commercial Ql Non commerical Windows Qt Windows Qt X11 Qt Mac and Qt Embedded or with modified versions of Qt that use the same license as Qt and distribute linked combinations including the two You must obey the GNU General Public License
36. Spatial Data Transfer Standard Grids with some limitations e USGS ASCII DEM e Erdas Imagine Because the raster implementation in QGIS is based on the GDAL library other raster formats implemented in GDAL are also likely to work but have not yet been tested See Appendix A 2 for more details QGIS 0 8 User Guide 36 5 3 Loading raster data in QGIS 5 3 Loading raster data in QGIS Fg En Raster layers are loaded either by clicking on the Load Raster icon or by selecting the View gt Add Raster Layer menu option More than one layer can be loaded at the same time by holding down the Control key and clicking on multiple items in the file dialog Please refer to section 8 2 if you intend to load GRASS rasterdata 5 4 Raster Properties To view and set the properties for a raster layer right click on the layer name This displays the raster layer context menu that includes a number of items that allow you to Figure 9 Raster context menu Properties Zoom to layer extent EI Add to overview a Remove from overview x Remove Rename Add group TS Expand all Collapse all X Show file groups e Open the properties dialog e Zoom to the full extent of the raster e Show the raster in the map overview window e Remove the layer from the map e Rename the layer e Add a layer group e Expand legend tree view QGIS 0 8 User Guide 37 5 4 Raster Properties e Collapse legend tree view e Show file groups Ch
37. The map composer is a feature that provides improved layout and printing capabilities The composer allows you to add elements such as the QGIS map canvas legend scalebar images and text You can size and position each item and adjust the properties to create your layout The result can be printed exported as an image or exported to SVG To access the map composer click on the Print button in the toolbar or choose Print from the File menu 9 1 Using Map Composer To use the map composer first add the layers you want to print to QGIS The layers should be rendered and symbolized to your liking prior to composing the map Opening the map composer provides you with a blank canvas to which you can add the current map view legend scalebar and text Figure Z shows the initial view of the map composer before any elements are added The map composer has two tabs General and Item The General tab allows you to set the paper size orientation and resolution for the map The tem tab displays the properties for the currently selected map element By selecting an element on the map eg legend scalebar text etc and clicking on the tem tab you can customize the settings You can add multiple elements to the composer This allows you to have more than one map view and legend in the composer Each element has its own properties and in the case of the map its own extent 9 1 1 Adding a Map to the Composer To add the QGIS map canva
38. Why is all this so new 2 1 2 Vector Data Vector data is also used in geospatial applications If you stayed awake during trigonometry and coordinate geometry classes you will already be familiar with some of the qualities of vector data In its simplest sense vectors are a way of describing a location by using a set of coordinates Each coordinate refers to a geographic location using a system of x and y values This can be thought of in reference to a Cartesian plane you know the diagrams from school that showed an x and y axis You might have used them to chart declining retirement savings or increasing compound mortgage interest but the concepts are essential to geospatial data analysis and mapping There are various ways of representing these geographic coordinates depending on your purpose This is a whole area of study for another day map projections Vector data takes on three forms each progressively more complex and building on the former 1 Points A single coordinate x y represents the discrete geographic location 2 Lines Multiple coordinates x1 y1 x2 y2 x3 y4 xn yn strung together in a certain order Like drawing a line from Point x1 y1 to Point x2 y2 and so on These parts between each point are considered line segments They have a length and the line can be said to have a direction based on the order of the points Technically a line is a single pair of coordinates connected together whereas a li
39. am is not restricted and the output from the Program is covered only if its contents constitute a work based on the Program independent of having been made by running the Program Whether that is true depends on what the Program does 1 You may copy and distribute verbatim copies of the Program s source code as you receive it in any medium provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer of warranty keep intact all the notices that refer to this License and to the absence of any warranty and give any other recipients of the Program a copy of this License along with the Program You may charge a fee for the physical act of transferring a copy and you may at your option offer warranty protection in exchange for a fee 2 You may modify your copy or copies of the Program or any portion of it thus forming a work based on the Program and copy and distribute such modifications or work under the terms of Section 1 above provided that you also meet all of these conditions a You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change b You must cause any work that you distribute or publish that in whole or in part contains or is derived from the Program or any part thereof to be licensed as a whole at no charge to all third parties under the terms of this License c If the modified program normally reads c
40. ame for the new layer Use the delimeter box to specify what the delimeter is for your file e g space commar or tab Note this box accepts regex entries so use t for tab and Delimited text file nan gnis_no_east_hemi_tabbed txt D Layer name Delimiter k X field Y field name aa Add Layer Close Figure 27 Selecting the X and Y Fields Greate a Layer from a Delimited Text File ee be aoe Delimited Text Layer gan pte t Description Select the file containing delimited text with latlon coordinates that you would like to use as a point layer and this plugin will do the job for you Use the layer name box to specify the legend name for the new layer Use the delimeter box to specify what the delimeter is for your file e g space commar or tab 1 Note this box accepts regex entries so use t for tab and 5 ennn Atarnhaneinn a dalimatar_ nrace tha narea k Delimited text file hianignis_no_east_hemi_tabbedtxt i l Layer name Geographic Names Delimiter fe X field longdec v Yfield latdec bal Help Parse Add Layer Close QGIS 0 8 User Guide 78 10 3 Using the Delimited Text Plugin Figure 28 Delimited Text Layer Added to QGIS Quantum GIS 0 4 0devel34 Pumpkin File View Tools Delimited Text Launcher Help 174 08954442 68 2282088602 QGIS 0 8 User Guide 79 11 Help and Support 11 1 Maili
41. ame way as described in Section 4 5 TJabove 4 6 Query Builder The Query Builder allows you to define a subset of a table and display it as a layer in QGIS It can be used for all OGR supported formats GRASS files and PostGIS layers For example if you have a towns layer with a population field you could select only larger towns by entering population gt 100000 in the SQL box of the query builder Figure B shows an example of the query builder populated with data from a PostGIS layer with attributes stored in PostgreSQL Figure 8 Query Builder Tabelle admin98 in Datenbank postgis auf Host localhost Benutzer holl m Felder Werte gid Ajman fips_admin Ali Sabih gmi_admin Amman admin_name Asir fips_cntry gmi_cntry entryznama Stichprobe a reman m Operatoren HNLICH IN NOTIN ILIKE UND ODER NICHT SQL where clause admin_name Alaska L schen Abbrechen The query builder lists the layer s database fields in the list box on the left You can get a sample of QGIS 0 8 User Guide 0 4 4 6 Query Builder the data contained in the highlighted field by clicking on the Sample button This retrieves the first 25 distinct values for the field from the database To get a list of all possible values for a field click on the All button To add a selected field or value to the query double
42. an upload command for your device and click the Update device button The name will be listed in the device menus in the upload and download windows and can be any string The download command is the command that is used to download data from the device to a GPX file This will probably be a GPSBabel command but you can use any other command line program that can create a GPX file QGIS will replace the keywords type in and out when it runs the command type will be replaced by w if you are downloading waypoints r if you are downloading routes and t if you are downloading tracks These are command line options that tell GPSBabel which feature type to download in will be replaced by the port name that you choose in the download window and out will be replaced by the name you choose for the GPX file that the downloaded data should be stored in So if you create a device type with the download command gpsbabel type i garmin o gpx in out this is actually the download command for the predefined device type Garmin serial and then use it to download waypoints from port dev ttySO to the file output gpx QGIS will replace the keywords and run the command gpsbabel w i garmin o gpx dev ttySO output gpx The upload command is the command that is used to upload data to the device The same keywords are used but in is now replaced by the name of the GPX file for the layer that is being u
43. are gathered on a need to know basis so it may well be that a given layers statistics have not yet been collected Tip 19 GATHERING RASTER STATISTICS To gather statistics for a layer select pseudocolor rendering and click the Apply button Gathering statistics for a layer can be time consuming Please be patient while QGIS examines your data 5 4 4 Pyramids Tab Large resolution raster layers can slow navigation in QGIS By creating lower resolution copies of the data pyramids performance can be considerably improved as QGIS selects the most suitable resolution to use depending on the level of zoom You must have write access in the directory where the original data is stored to build pyramids Several resampling methods can be used to calculate the pyramides e Average e Nearest Neighbour e Average Magphase Please note that building pyramids may alter the original data file and once created they cannot be removed If you wish to preserve a non pyramided version of your raster make a backup copy prior to building pyramids QGIS 0 8 User Guide 40 5 4 Raster Properties 5 4 5 Histogram Tab The histogram tab allows you to visualize the histogram of your rasterdata This is useful to get an idea about the pixel distribution Two different chart types are allowed Barcharts and Linegraphs QGIS 0 8 User Guide 41 6 Working with OGC Data 6 1 What is OGC Data The Open Geospatial Consortium OGC is an internat
44. ase table for a given layer Here you can add modify or create new database tables for the current layer QGIS 0 8 User Guide 56 8 5 Region Tool Tip 29 GRASS EDIT PERMISSIONS You must be the owner of the GRASS mapset you want to edit It is impossible to edit vectors in mapsets which are not yours even if you have write permissions 8 5 Region Tool Ki The current region window in GRASS is very important for all raster modules All new created rasters have the extension and resolution of the current region regardless their original region The region is stored in LOCATION MAPSET WIND file and it defines north south east west number of columns number of rows horizontal and vertical spatial resolution It is possible to switch on off the GRASS region in QGIS canvas using the Display Current GRASS Region button With the Edit Current GRASS Region you can open a tool in which you can change the current region and symbology of the GRASS region rectangle on the QGIS canvas When the tool is running it is also possible to select a new region interactively with your mouse on the QGIS canvas 8 6 GRASS Toolbox aR The GRASS toolbox provides analytic functions from GRASS within QGIS To use the GRASS toolbox you need to have opened a mapset where you have write permission This is needed because QGIS will most probably create new datasets which need to be written to a valid mapset Therefor you need to start QGIS from within
45. ature e Field layer feature attribute table identification Tip 28 CREATING ADDITIONAL LAYERS WITH QGIS If you like to add more layers to your dataset just add a new number in the Field layer entry box and press return In the Table tab you can create your new table connected to your new layer 8 4 3 Settings Tab This tab allows you to set the snapping in screen pixels This is the threshold in pixels in which new points or line ends are snapped to existing nodes This helps prevent gaps or dangles between QGIS 0 8 User Guide 55 8 4 Digitizing and Editing Tools Table 4 GRASS Digitizing Tools Purpose Teon Pms o o S new Boundary die new boundary tirish by selecting rew00 W Delete vertex delete one vertex from existing line confirm selected vertex by another click select existing line and click on new position Split line split an existing line to 2 parts LA Delete line delete existing line confirm selected line by another click Edit attributes edit attributes of existing element note that one element can represent more features see above close digitizing session rebuilds topology afterwards boundaries The default is set to 10 pixels 8 4 4 Symbology Tab This tab allows you to view and set symbology and color settings for various geometry types and their topological status e g closed opened boundary 8 4 5 Table Tab This tab provides information about the datab
46. ayer Alternately you can use the E start editing or Stop editing buttons from the toolbar to toggle the editing mode Tip 10 EDITING A MAP IS DIFFERENT TO EDITING AN ATTRIBUTE TABLE In this version of QGIS the Start editing Stop editing couplet on the map view acts separately to the Start Editing Stop Editing couplet on the attribute table Tip 11 SAVE REGULARLY Remember to toggle Allow editing off or select the Stop editing button regularly This allows you to save your changes thus far and also confirms that your data source can accept all your changes Once the layer is in edit mode markers will appear at the vertices You can perform the following editing functions e Add Features e Add Vertices of a Feature e Move Vertices of a Feature e Delete Vertices of a Feature e Cut Selected Features e Copy Selected Features e Paste Selected Features e Delete Selected Features Adding Features Before you start adding features use the pan and zoom tools to first navigate to the area of interest Then you can use the Capture Point Capture Line or Capture Polygon icon on the toolbar to put the QGIS cursor into digitizing mode For each feature you first digitize the geometry then enter its attributes QGIS 0 8 User Guide 29 4 5 Editing Tip 12 CONCURRENT EDITS This version of QGIS does not track if somebody else is editing a feature at the same time as you The last writer wins Tip 13 ZOOM IN BEFORE EDITING Before
47. beyond its end you will need to move the terminating vertex first then add a new vertex where the terminus used to be Moving Vertices of a Feature New in v0 8 You can add new verticies to a feature by using the Move Vertex icon on the toolbar QGIS 0 8 User Guide 31 4 5 Editing Deleting Vertices of a Feature New in v0 8 You can add new verticies to a feature by using the Delete Vertex icon on the toolbar Note it doesn t make sense to delete the vertex of a Point feature Delete the whole feature instead Similarly a one vertex line or a two vertex polygon is also fairly useless and will lead to unpredictable results elsewhere in QGIS so don t do that Warning A vertex is identified for deletion as soon as you click the mouse near an eligible feature To undo you will need to toggle Editing off and then discard your changes Of course this will mean that other unsaved changes will be lost too Cutting Copying and Pasting Features New in v0 8 Selected features can be cut copied and pasted between layers in the same QGIS project as long as destination layers are set to Allow editing beforehand Features can also be pasted to external applications as text That is the features are represented in CSV format with the geometry data appearing in the OGC Well Known Text WKT format However in this version of QGIS text features from outside QGIS cannot be pasted to a layer within QGIS Tip 16 CONGRUENCY OF PASTE
48. bluemarbe naturakarth naturalearth ost srtm30_topex E f kratzenberg resolution muell naturalearth_europa naturalearth west f PERMANENT Nain 646839 a redslob South 7 raster fies availabe in mapset kratzenberg LC_SR_W_16200_Ost bgr LC_SR_W_16200_West bgr muell u GRASS Tools world Il holl Rows 2261 raster files availabe in mapset holl bluemarble_ng naturalearth_001 naturalearth_1 16 3 Format integer 1bytes GRASS gt g list help Minimum O value Description Lists availabe GRASS data base files of the user specified data type to stand Maximum 32767 value Usage Data generated by r composite g list type datatype mapset string description Comments r composite Flags red bluemarble_ng red f verbose listing also list map titles green bluemarble_ng gn blue Parameters bluemarbk_ng blue type data type kveb 32 output bluemarbe_ng options rast rast3d vect oldvect asciivect icon labd region region3d group 3dview mapset mapeet to list default current search path Where type is one of rast raster files rast3d raster3D files vect binary vector files a GRASS browser inside the toolbox b GRASS shell inside the toolbox 8 7 Creating new vectors With this version of QGIS it is also possible to create new vectors from within GRASS very easily Just select Plu
49. click on it You can use the various buttons to construct the query or you can just type it into the SQL box To test a query click on the Test button This will return a count of the number of records that will be included in the layer When satisfied with the query click Ok The SQL for the where clause will be shown in the SQL column of the layer list Tip 18 CHANGING THE LAYER DEFINITION You can change the layer definition after it is loaded by altering the SQL query used to define the layer To do this open the vector layer properties dialog by double clicking on the layer in the legend and click on the Query Builder button on the General tab See Section 4 3 for more information 4 6 1 Query PostGIS layers To query a loaded PostGIS layer there are two options The first is to click on the button Open Table to open the attribute table of the PostGIS layer Then choose the Advanced button at the bottom This starts the Query Builder that allows to define a subset of a table and display it as described in Section 4 6 The second option to load a PostGIS layer is to open the Layer Properties dialog by double clicking on the PostGIS layer name in the legend or by right clicking and choosing Properties from the popup menu In the tab General click the Query Builder button at the bottom 4 6 2 Query OGR formats and GRASS files To query a loaded GRASS file or OGR supported format you currently need to click on the button Open Table to
50. contains four important components as numbered in Figure H2 and described below Figure 12 Projection Dialog GNU Linux Project Properties lt galileo gt Geographic Coordinate Systems Projected Coordinate Systems Abers Equal Area NAD 27 Alaska Albers meters NAD27 Alaska Albers NAD83 BC Albers Cassini Krovak Oblique Conic Conformal QGIS SRSID 209 cy PostGIS SRID 5000 proj aea at_1 55 t_2 65 at_0 50 lon_O 154 x_O 0 y_O 0 ellps clrk66 datum NAD 27 searr F Postgis SRAID O EPSG ID O GISSASID O Name C a 1 Enable projections this checkbox is used to enable or disable OTF projection When off no projection takes place and each layer is drawn using the coordinates as read from the data source When on the coordinates in each layer are projected to the coordinate system of the map canvas 2 Projections this is a list of all projection supported by QGIS including Geographic Projected and Custom coordinate systems To use a coordinate system select it from the list by QGIS 0 8 User Guide 50 7 3 Custom Projections expanding the appropriate node and selecting the projection The active projection is pre selected 3 Proj4 text this is the projection string used by the Proj4 projection engine This text is read only and provided for informational purposes 4 Search if you know the PostGIS EPSG QGIS SRSID identifier or the name for a projection you can use
51. ct Properties see SectionB 7 Custom Projection see Section 7 3 Options see Section 8 8 e Plugins Futher menu items are added by plugins as they are loaded Plugin Manager e Help Help Contents QGIS Homepage QGIS Sourceforge About Check QGIS Version 3 4 2 Toolbars The toolbars provide access to most of the same functions as the menus plus additional tools for interacting with the map Each toolbar item has popup help available Hold your mouse over the item and a short description of the tool s purpose will be displayed Every menubar can be moved around according to your needs Additionally every menubar can be switched off using your right mouse button context menu Tip 2 REAPPEARING TOOLBARS If you have accidentally hidden all your toolbars you can get them back by choosing Show most toolbars from the View Toolbars menu QGIS 0 8 User Guide 10 3 4 QGIS GUI 3 4 3 Map Legend The map legend area is used to set the visibility and z ordering of layers Z ordering means that layers listed nearer the top of the legend are drawn over layers listed lower down in the legend The checkbox in each legend entry can be used to show or hide the layer Layers can be grouped in the legend window by adding a layer group and dragging layers into the group To do so go with the mouse to the legend window right click choose Add group A new folder appears Now drag the layers to t
52. discuss Steering Committee issues related to overall management and direction of Quantum GIS You can subscribe to this list at http mrcc com cgi bin mailman listinfo qgis psc QGIS 0 8 User Guide 80 11 2 IRC You are welcome to subscribe to any of the lists Please remember to contribute to the list by answering questions and sharing your experiences Note that the qgis commit and qgis trac are designed for notification only and not meant for user postings 11 2 IRC We also maintain a presence on IRC visit us by joining the qgis channel on irc freenode net Please wait around for a response to your question as many folks on the channel are doing other things and it may take a while for them to notice your question Commercial support for QGIS is also available Check the website http qgis org content view 90 91 for more information If you missed a discussion on IRC not a problem We log all discussion so you can easily catch up Just go to http logs qgis orgjand read the IRC logs 11 3 BugTracker While the qgis users mailing list is useful for general how do do xyz in QGIS type questions you may wish to notify us about bugs in QGIS You can submit bug reports using the QGIS bug tracker at http svn qgis org trac When creating a new ticket for a bug please provide an email address where we can request additional information Please bear in mind that your bug may not always enjoy the priority you might hop
53. discussion 4 4 1 Defining Actions Attribute actions are defined from the vector layer properties dialog To define an action open the vector layer properties dialog and click on the Actions tab Provide a descriptive name for the action The action itself must contain the name of the application that will be executed when the action is invoked You can add one or more attribute field values as arguments to the application When the action is invoked any set of characters that start with a followed by the name of a field will be replaced by the value of that field The special characters will be replaced by the value of the field that was selected from the identify results or attribute table see Using Actions below Double quote marks can be used to group text into a single argument to the program script or command Double quotes will be ignored if proceeded by a backslash Two example actions are shown below e konqueror http www google com search q nam e konqueror http www google com search q hh In the first example the web browser konqueror is invoked and passed a URL to open The URL performs a Google search on the value of the nam field from our vector layer Note that the application or script called by the action must be in the path or you must provided the full path To be sure we could rewrite the first example as opt kde3 bin konqueror http www google com search q nam This will ensure that the konqueror applicat
54. e for depending On its severity Some bugs may require significant developer effort to remedy and the manpower is not always available for this Feature requests can be submitted as well using the same ticket system as for bugs Please make sure to select the type enhancement If you have found a bug and fixed it yourself you can submit this patch also Again the lovely trac ticketsystem at http svn qgis org trac has this type as well Select patch from the type menu Someone of the developers will review it and apply it to QGIS Please dont be alarmed if your patch is not applied straight away developers may be tied up with other committments 11 4 Blog The QGIlS community also runs a weblog BLOG at http blog qgis org which has some interesting articles for users and developers as well You are invited to contribute to the blog after registering yourself QGIS 0 8 User Guide 81 11 5 Wiki 11 5 Wiki Lastly we maintain a WIKI web site at http wiki qgis org where you can find a variety of useful information relating to QGIS development release plans links to download sites message translation hints and so on Check it out there are some goodies inside QGIS 0 8 User Guide 82 A Supported Data Formats A 1 Supported OGR Formats At the date of this document the following formats are supported by the OGR library Formats known to work in QGIS are indicated in bold e Arc Info Binary Coverage e Comma Sepa
55. e is done using the same method as with a shapefiles and MapInfo layers Click on the Add a vector layer toolbar button to open the layer dialog and change the file type filter to All files Navigate to the coverage directory and select one of the following files if present in your coverage e lab to load a label layer polygon labels or standing points e cnt to load a polygon centroid layer e arc to load an arc line layer e pal to load a polygon layer 4 2 PostGIS Layers PostGIS layers are stored in a PostgreSQL database The advantage of PostGIS is the spatial indexing filtering and query capability Using PostGIS vector functions such as select and identify work more accurately than with OGR layers in QGIS To use PostGIS layers you must e Create a stored connection in QGIS to the PostgreSQL database if one is not already defined e Connect to the database e Select the layer to add to the map e Optionally provide a SQL where clause to define which features to load from the layer e Load the layer 4 2 1 Creating a stored Connection od The first time you use a PostGIS data source you must create a connection to the PostgreSQL database that contains the data Begin by clicking on the Add a PostGIS Layer toolbar button The Add PostGIS Table s dialog will be displayed To access the connection manager click on the New button to display the Create a New PostGIS Connection dialog The parameters required for
56. eSQL build directory The contrib subdirectory is located in the directory created in step 3 of the PostgreSQL installation process 3 Change to the postgis subdirectory 4 Edit the Makefile to enable GEOS support see the note above 5 PostGIS provides a manual in the doc html subdirectory that explains the build process see the Installation section 6 The quick and dirty steps to install PostGIS are cd contrib gunzip postgis 1 x x tar gz tar xvf postgis 1 x x tar cd postgis 1 x x make sudo make install createlang plpgsql yourtestdatabase psql d yourtestdatabase f lwpostgis sql psql d yourtestdatabase f spatial_ref_sys sql The better way to install PostGIS is to carefully follow the instructions in the PostGIS manual in the doc html subdirectory or the online manual at http postgis refractions net docs QGIS 0 8 User Guide 98 E 5 SQLite3 E 5 SQLite3 SQLite3 is used to manage the projections database and store persistent data such as spatial bookmarks Download the latest 3 x version of SQLite from http www sqlite org 9 Untar the distribution and configure make make install Note SQLite 3 x is included on Mac OS X 10 4 E 6 GDAL OGR The GDAL and OGR libraries provide support for raster and vector data formats QGIS makes use of both of these libraries which come bundled in one distribution Note A GNU Linux binary of GDAL is available at http www gdal org If you choose
57. ection You can then start QGIS and add the plugins one at a time from the Plugin Manger to determine which is causing the problem QGIS 0 8 User Guide 66 10 1 An Introduction to Using Plugins Figure 19 Plugin Manager QGIS Plugin Manger Plugin Directory usr ocaliqgis ibqgis To bad a plugin click the checkbox next to the plugin and click Ok Description O Add Delimited Text Layer Version 0 2 This plugin provides support for delimited text files co L CopyrightLabel Version 0 1 This plugin overlays copyright information on the renc O Georeferencer Version 0 1 The georeferencer plugin is a tool for adding projectic O GPS Tools Version 0 1 Tools for loading and importing GPS data GRASS 0 1 GRASS layer O Graticule Creator Version 0 1 A graticule building plugin NorthArrow Version 0 1 This plugin displays a north arrow overlayed onto the CO PostgresSQL Geoprocessing Version 0 1 Geoprocessing functions for working with Postgre SQI O ScaleBar Version 0 1 Plugin to draw scale baron map O spit Version 0 1 Shapefile to Postgre SQL PostGIS Import Tool K We Sekct All Clear All Ok 10 1 3 Data Providers Data Providers are special plugins that provides access to a data store By default QGIS supports PostGIS layers and disk based data stores supported by the GDAL OGR library Appendix A1 A Data Provider plugin extends the ability of QGIS to use other data sources Data Provider plugins are
58. editing a layer you should zoom in to your area of interest first This avoids waiting while all the vertex markers are rendered across the entire layer To digitize the geometry left click on the map area to create the first point of your new feature For lines and polygons keep on left clicking for each additional point you wish to capture When you have finished adding points right click anywhere on the map area to confirm you have finished entering the geometry of that feature The attribute window will appear allowing you to enter the information for the new feature Figure 6 shows setting attributes for a fictitious new river in England Figure 6 Vector Digitizing Attributes Capture Dialog ga Quantum GIS 0 8 0 Titan Preview 1 lt galileo gt X Eie View Layer Settings Plugins Help 38443 PREBBAa OF 1HB6OM PARKRGACO sHuaonns SPSSeRREEBE v Besley 5 xe x S Files Eq new_river S Rj Polbnda_eurnasia_pg Efiter Attribute Values lt b 1 x man dey S Files Soak 1 55 903 5581 X Render l QGIS 0 8 User Guide 30 4 5 Editing Tip 14 VERTEX MARKERS This version of QGIS does not allow you to change the vertex markers used Tip 15 ATTRIBUTE VALUE TYPES In the current version of QGIS the attributes dialog box does not check that the data entered matches the type expected e g numeric vs
59. efore by modifying or distributing the Program or any work based on the Program you indicate your acceptance of this License to do so and all its terms and conditions for copying distributing or modifying the Program or works based on it 6 Each time you redistribute the Program or any work based on the Program the recipient automatically receives a license from the original licensor to copy distribute or modify the Program subject to these terms and conditions You may not impose any further restrictions on the recipients exercise of the rights granted herein You are not responsible for enforcing compliance by third parties to this License 7 If as a consequence of a court judgment or allegation of patent infringement or for any other reason not limited to patent issues conditions are imposed on you whether by court order agreement or otherwise that contradict the conditions of this License they do not excuse you from the conditions of this License If you cannot distribute so as to satisfy simultaneously your obligations under this License and any other pertinent obligations then as a consequence you may not distribute the Program at all For example if a patent license QGIS 0 8 User Guide 88 would not permit royalty free redistribution of the Program by all those who receive copies directly or indirectly through you then the only way you could satisfy both it and this License would be to refrain entirely from distribution o
60. election made The results of the query are returned in plain text The formatting of this text is dependent on the particular WMS server used 6 2 5 Viewing Properties Once you have added a WMS server you can view its properties by right clicking on it in the legend and selecting Properties Metadata Tab The Metadata tab displays a wealth of information about the WMS server generally collected from the Capabilities statement returned from that server Many definitions can be gleaned by reading the WMS standards 7 lg but here are a few handy definitions e Server Properties WMS Version The WMS version supported by the server QGIS 0 8 User Guide 46 6 2 WMS Client Image Formats The list of MIME types the server can respond with when drawing the map QGIS supports whatever formats the underlying Qt libraries were built with which is typically at least image png and image jpeg Identity Formats The list of MIME types the server can respond with when you use the Identify tool Currently QGIS supports the text plain type e Layer Properties Selected Whether or not this layer was selected when its server was added to this project Visible Whether or not this layer is selected as visible in the legend Not yet used in this version of QGIS Can Identify Whether or not this layer will return any results when the Identify tool is used on it Can be Transparent Whether or not
61. ent Limitations Not all possible WMS Client functionality had been included in this version of QGIS Some of the more notable exceptions follow QGIS 0 8 User Guide 47 6 2 WMS Client Editing WMS Layer Settings Once you ve completed the Add WMS layer procedure there is no ability to change the settings A workaround is to delete the layer completely and start again WMS Servers Requiring Authentication Only public WMS servers are accessible There is no ability to apply a user name and password combination as an authentication to the WMS server QGIS 0 8 User Guide 48 7 Working with Projections QGIS supports on the fly OTF projection of vector layers This feature allows you to display layers with different coordinate systems and have them overlay properly 7 1 Overview of Projection Support QGIS has support for approximately 2 700 known projections Projections are stored in a Sqlite database that is installed with QGIS Normally you do not need to manipulate the database directly In fact doing so may cause projection support to fail Custom projections are stored in a user database See Section Z 3 for information on managing your custom projections The projections available in QGIS are based on those defined by EPSG and are largely abstracted from the spatial_references table in PostGIS version 1 x Note that the identifiers used in QGIS do not correspond to the EPSG or PostGIS spatial reference identifiers The EPSG
62. eone else and passed on we want its recipients to know that what they have is not the original so that any problems introduced by others will not reflect on the original authors reputations Finally any free program is threatened constantly by software patents We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses in effect making the program proprietary To prevent this we have made it clear that any patent must be licensed for everyone s free use or not licensed at all The precise terms and conditions for copying distribution and modification follow TERMS AND CONDITIONS FOR COPYING DISTRIBUTION AND MODIFICATION QGIS 0 8 User Guide 86 0 This License applies to any program or other work which contains a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License The Program below refers to any such program or work and a work based on the Program means either the Program or any derivative work under copyright law that is to say a work containing the Program or a portion of it either verbatim or with modifications and or translated into another language Hereinafter translation is included without limitation in the term modification Each licensee is addressed as you Activities other than copying distribution and modification are not covered by this License they are outside its scope The act of running the Progr
63. ering can be controlled in the following ways e Temporarily suspending rendering e Setting an option to control the visibility of layers when they are added 3 5 3 Suspending Rendering To suspend rendering click the Render checkbox in the lower right corner of the statusbar When the Render box is not checked QGIS does not redraw the canvas in response to any of the events described in Section 3 5 Examples of when you might want to suspend rendering include e Add many layers and symbolize them prior to drawing e Add one or more large layers and set scale dependency before drawing e Add one or more large layers and zoom to a specific view before drawing e Any combination of the above Checking the Render box enables rendering and causes and immediate refresh of the map canvas 3 5 4 Setting Layer Add Option You can set an option to always load new layers without drawing them This means the layer will be added to the map but its visibility checkbox in the legend will be unchecked by default To set this option choose Preferences from the Settings menu and click on the Rendering tab Check the New layers added to the map are not displayed checkbox Any layer added to the map will be off invisible by default 3 5 5 Updating the Map Display During Rendering You can set an option to update the map display as features are drawn By default QGIS does not display any features for a layer until the entire layer has been rendered To
64. f the Program If any portion of this section is held invalid or unenforceable under any particular circumstance the balance of the section is intended to apply and the section as a whole is intended to apply in other circumstances It is not the purpose of this section to induce you to infringe any patents or other property right claims or to contest validity of any such claims this section has the sole purpose of protecting the integrity of the free software distribution system which is implemented by public license practices Many people have made generous contributions to the wide range of software distributed through that system in reliance on consistent application of that system it is up to the author donor to decide if he or she is willing to distribute software through any other system and a licensee cannot impose that choice This section is intended to make thoroughly clear what is believed to be a consequence of the rest of this License 8 If the distribution and or use of the Program is restricted in certain countries either by patents or by copyrighted interfaces the original copyright holder who places the Program under this License may add an explicit geographical distribution limitation excluding those countries so that distribution is permitted only in or among countries not thus excluded In such case this License incorporates the limitation as if written in the body of this License 9 The Free Software Foundation may publ
65. for another map canvas Itis possible to export the result as an image by clicking on the Export as image button QGIS 0 8 User Guide 64 9 1 Using Map Composer Figure 18 Map Composer with map view legend scalebar and text added MainWindow lt galileo gt f a ww SRAQRO BIBER Quantum GIS Map of Germany Extent calculate scale Width 172 Height 153 Sa Legend Symbolscak Polgrercer AMFRIM SCHLESWIS HOR STERN E apenworrremeens E savern Font size scak E cern GG noanueaenersacesen GE panceneuna E ien Frame GB Fovarsceeswis HOLSTER GB uera E pester s To export the composer canvas as an SVG Scalable Vector Graphic click on the Export as SVG button Note Currently the SVG output is very basic This is not a QGIS problem but a problem of the underlaying Qt library This will be sorted out in future versions QGIS 0 8 User Guide 65 10 Using Plugins 10 1 An Introduction to Using Plugins QGIS has been designed with a plugin architecture This allows new features functions to be added to the application Many of the features in QGIS are actually implemented as plugins There are two types of plugins in QGIS core and user contributed A core plugin is maintained by the QGIS development team and is part of every QGIS distribution A user contributed plugin is an external plugin that is maintained by the individual author The QGIS SVN website http svn qgis org serves some user cont
66. fter you have installed the required libraries you are ready to build QGIS Download and untar the QGIS distribution and change to the QGIS source directory You have two options for building and installing QGIS Quick and Dirty and the right way F 1 Quick and Dirty If you don t need PostgreSQL support and have installed GDAL you can configure and build QGIS by changing to the distribution directory and typing configure make sudo make install The above assumes that the gdal config program is in your PATH See the next section for the full configuration instructions QGIS 0 8 User Guide 102 F 2 Configuring QGIS the right way F 2 Configuring QGIS the right way To see the configure options available change the the QGIS directory and enter configure help Among other options there are six that are important to the success of the build with qtdir dir qt installation directory default qtdir with gdal path full path to gdal config script e g with gdal usr local bin gdal config with postgresql path PostgreSQL PostGIS support full path to pg_config with grass dir grass support full path to grass binary package with geos path Full path to geos config script e g with geos usr local bin geos config with sqlite3dir dir sqlite3 installation directory e g with sqlite3 usr local F 2 1 Qt4 The configure script will detect Qt unless it is installed in a non standard
67. gins gt GRASS gt Create new GRASS layer from the toolbar give a new name in the text box and start digitizing If you encounter a greyed out button make sure you have a working mapset enabled If you forgot how to enable have a look at sec Since GRASS is able to organize all sort of geometries in on layer there is no need to select the geometry This only applies to shapefile creation see sec 4 5 2 Some hints to make your digitizing more useful e Make sure to create an attribute table with its needed columns before you start digitizing if you QGIS 0 8 User Guide 60 8 7 Creating new vectors Figure 16 Module generated through parsing the XML file G GRASS Tools Spearfishoo hollaaleles Modules Browser ZP L Options Output Manual m Name of input vector map ____ bd m Buffer distance in map units Name of output vector map like to assign attributes to your digitized object Go to the table tab inside the digitize window e If you plan to create to polygon layer consider setting the mode to No category Then start digitizing the boundaries which actually do not need an entry in the attribute table If you have done this change back to Next not used and start digitizing the centroids which hold the attribute information of a polygon QGIS 0 8 User Guide 61 9 Map Composer
68. he folder symbol It is then possible to toggle the visibility of all the layers in the group with one click To bring layers out of a group go with the mouse to the layer symbol right click choose make to toplevel item To give the folder a new name choose Rename in the right click menu of the group If several vector data sources have the same vector type and the same attributes their symbolisations may be grouped This means that if the symbolisation of one data source is changed the others automatically have the new symbolisation as well To group symbologies open the right click menu in the legend window and choose Show file groups The file groups of the layers appear It is now possible to drag a file from one file group into another one If this is done the symbologies are grouped Note that QGIS only permits the drag if the two layers are able to share symbology same vector type and same attribute 3 4 4 Map View This is the business end of QGIS maps are displayed in this area The map displayed in this window will depend on the vector and raster layers you have chosen to load see sections that follow for more information on how to load layers The map view can be panned shifting the focus of the map display to another region and zoomed in and out Various other operations can be performed on the map as described in the toolbar description above The map view and the legend are tightly bound to each other
69. iles Figure 4 QGIS with vmap0 Shapefile of Spain loaded gt Quantum GIS 0 8 0 Titan Preview 1 lt galileo gt Eie View Layer Settings Plugins Help JHBasSs YREEB HREOC OS SSSSVRSBBAAR vo SPANA Legend F o 3 Avon E m Az zawiyan sacau sacs KISKUN BISADEN WURTTEMBERG fsasan W saku MESALKesIR BANcHaz sanzant Bsananya H BARDSEY ISLAND WALES EESARENTSOYA SVALBARD AN J BARKHOMODDEN SVALBARD 7 BARRA SCOTLAND BISASEL LANDSCHAFT BASEL STADT EESASILICATA J BASSE NORMANDIE EESASTIANOYANE SVALBARD A satna te Pe BAYAN OLGlY S EXTREMADURA J 5AYANHONGOR SAveERN I BEAR ISLAND MUNSTER WeEcHanR messa seuaia PSEKes F BELGORODSKAYA OBLAST 7 BELLE ILE BRETAGNE EESENBECULA SCOTLAND J BERAT J EERLN seRn RPSERNERAY SCOTLAND JJ 8 ALA PODLASKA 2 43 37 32 B Render e Load a shapefile e Open the Layer Properties dialog by double clicking on the shapefile name in the legend or by right clicking and choosing Properties from the popup menu e In the tab General click the Create button on the Spatial Index panel 4 1 3 Loading a MapInfo Layer To load a MapInfo layer click on the Add a vector layer toolbar bar button and change the file type filter to MapInfo mif tab MIF TAB and select the layer you want to load QGIS 0 8 User Guide 20 4 2 PostGIS Layers 4 1 4 Loading an Arclnfo Coverage Loading an an Arclnfo coverag
70. ils 23 loading layers 27 22 password 22 port 22 PostGIS 78 query builder 35 username Projections coordinate reference system 45 CRS 45 custom 51 enabling 60 specifying B1 WMS 45 working with 49 projects 5 Query Builder 84 adding fields 85 changing layer definitions 85 generating sample list B5 getting all values 35 testing queries B5 query builder GRASS 5 OGR 85 PostGIS B5 PostgreSQL B5 raster layers 41l context menu B7 108 data formats definition 36 GDAL implementation B6 georeferenced B6 histogram T icolor map inversion 89 loading B7 metadata 40 properties 38 40 pyramids 40 rendering interpretation 39 resolution pyramids 40 standard deviation 39 statistics supported channels 89 supported formats transparency rasters metadata 46 properties 46 WMS 42 rendering 12 options 3 scale dependent 2 suspending 3 update during drawing scale 13 security settings 22 shapefile format 18 loading 18 specification shapefiles 18 SHP files spatial bookmarks seebookmarks16 spatial index shapefiles 19 Start Editing 29 Stop Editing 29 QGIS 0 8 User Guide Index symbology changing 26 TAB files 18 toolbars 10 vector layers adding feature vertex B1 ArcInfo Coverage 21 copy feature cut feature deleting
71. in all respects for all of the code used other than Qt If you modify this file you may extend this exception to your version of the file but you are not obligated to do so If you do not wish to do so delete this exception statement from your version QGIS 0 8 User Guide 91 C Installation The described process within this document deals with the basic build process from source on NIX systems configure make sudo make install For operating systems like GNU Linux Windows and Mac OSX there are precompiled binaries where you mostly do not need to read further than the next three following subsections For current links to binary packages compair section D C 1 Installing GNU Linux Version For GNU Linux binary packages are available for various distributions such as Debian Ubuntu Fedora Mandriva or SUSE You can easily install the rom or deb binaries with the appropriate Package Manager C 2 Installing Windows Version Installing the Windows version of QGIS is simply a matter of running the user friendly setup wizard See the README WIN32 file for additional information regarding the Windows version of QGIS At version 0 74 the GRASS plugin was not yet available in Windows because no native GRASS port existed Since GRASS GIS is almost completely ported to MS Windows QGIS 0 8 now includes the GRASS plugin as well C 3 Installing Mac OS X Version To install the compressed disk image containing the OSX version
72. ion will be executed when the action is invoked The second example uses the notation which does not rely on a particular field for its value When the action is invoked the will be replaced by the value of the selected field in the identify results or attribute table QGIS 0 8 User Guide 27 4 5 Editing 4 4 2 Using Actions Actions can be invoked from either the dentify Results dialog or the Attribute table dialog To invoke an action right click on the record and choose the action from the popup menu Actions are listed in the popup menu by the name you assigned when defining the actions Click on the action you wish to invoke If you are invoking an action that uses the notation right click on the field value in the Identify Results dialog or the Attribute table that you wish to pass to the application or script Here is another example that pulls data out of a vector layer and inserts it into a file using bash and the echo command so it will only work on Gnu Linux and perhaps Mac OS X The layer in question has fields for a species name taxon_name latitude lat and longitude long would like to be able to make a spatial selection of a localities and export these field values to a text file for the selected record shown in yellow in the QGIS map area Here is the action to achieve this bash c echo taxon_name lat long gt gt tmp species_localities txt After selecting a few localities and runni
73. ional organization with more than 300 commercial governmental nonprofit and research organisations worldwide Its members develop and implement standards for geospatial content and services GIS data processing and exchange Describing a basic data model for geographic features an increasing number of specifications are developed to serve specific needs for interoperable location and geospatial technology including GIS Further information can be found under http www opengeospatial org Important OGC specifications are e WMS Web Map Service e WFS Web Feature Service e WCS Web Coverage Service e CAT Web Catalog Service e SFS Simple Features for SQL e GML Geography Markup Language OGC services are increasingly being used to exchange geospatial data between different GIS implementations and data stores QGIS can now deal with two of the above specifications being SFS though support of the PostgreSQL PostGIS data provider see Section 4 2 and WMS as a client 6 2 WMS Client New in v0 8 6 2 1 Overview of WMS Support 6 QGIS currently can act as a WMS client that understands WMS 1 1 1 1 1 and 1 3 servers It has particularly been tested against publicly accessible servers such as DEMIS and JPL OnEarth WMS servers act upon requests by the client e g QGIS for a raster map with a given extent set of layers symbolisation style and transparency The WMS server then consults its local data sources QGIS 0
74. ish revised and or new versions of the General Public License from time to time Such new versions will be similar in spirit to the present version but may differ in detail to address new problems or concerns Each version is given a distinguishing version number If the Program specifies a version number of this License which applies to it and any later version you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation If the Program does not specify a version number of this License you may choose any version ever published by the Free Software Foundation 10 If you wish to incorporate parts of the Program into other free programs whose distribution conditions are different write to the author to ask for permission For software which is copyrighted by the Free Software Foundation write to the Free Software Foundation we sometimes make exceptions for this Our decision will be guided by the two goals of preserving the free status of all derivatives of our free software and of promoting the sharing and reuse of software generally NO WARRANTY 11 BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE THERE IS NO WARRANTY FOR THE PROGRAM TO THE EXTENT PERMITTED BY APPLICABLE LAW EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND OR OTHER PARTIES PROVIDE THE PROGRAM AS IS WITHOUT WARRANTY OF ANY KIND EITHER EXPRESSED OR IMPLIED INCLUDING BUT
75. jrivers shp Command line option snapshot This option allows you to create a snapshot in PNG format from the current view This comes in handy when you have a lot of projects and want to generate snapshots from your data Currently it generates a PNG file with 800x600 pixels A filename can be added after snapshot Command line option lang Based on your locale QGIS selects the correct localization If you like to change your language you can provide another language with this option Command line option project Starting QGIS with an existing project file is also possible Just add the command line option project followed by your project name and QGIS will open with all layers loaded described in the given file Command line option extent To start with a specific map extent use this option You need to add the bounding box of your extent in the following order separated by a comma extent xmin ymin xmax ymax QGIS 0 8 User Guide 7 3 4 QGIS GUI 3 4 QGIS GUI When QGIS starts you are presented with the GUI as shown below the numbers 1 through 6 in blue ovals refer to the six major areas of the interface as discussed below Figure 1 Main window with spearfish sample data Quantum GIS 0 8 0 Titan Prev Eie View Layer Settings Plugins Help a i oad danns P PREOBAaA BF1BB46ER Raad a HEURES BSPSS9BRBRBBBAB o PPNM Legend amp RE Streams 1 i Roads 1 9 Elevation 10m B
76. kmark To create a bookmark 1 Zoom or pan to the area of interest 2 Select the menu option View gt New Bookmark or type Ctrl B 3 Enter a descriptive name for the bookmark up to 255 characters 4 Click OK to add the bookmark or Cancel to exit without adding the bookmark Note that you can have multiple bookmarks with the same name 3 9 2 Working with Bookmarks To use or manage bookmarks select the menu option View gt Show Bookmarks The bookmarks dialog allows you to zoom to or delete a bookmark You can not edit the bookmark name or coordinates 3 9 3 Zooming to a Bookmark From the Bookmarks dialog select the desired bookmark by clicking on it then click the Zoom To button You can also zoom to a bookmark by double clicking on it QGIS 0 8 User Guide 16 3 9 Spatial Bookmarks 3 9 4 Deleting a Bookmark To delete a bookmark from the Bookmarks dialog click on it then click the Delete button Confirm your choice by clicking Yes or cancel the delete by clicking No QGIS 0 8 User Guide 17 4 Working with Vector Data QGIS supports vector data in a number of formats including those supported by the OGR library data provider plugin such as ESRI shapefiles MapInfo MIF interchange format and MapInfo TAB native format QGIS also supports PostGIS layers in a PostgreSQL database using the PostgreSQL data provider plugin Support for additional data types eg delimited text is provided by additional data provide
77. l data stored In a nutshell there are two types of geospatial data in widespread use today This is in additional to traditional tabular data that is also widely used by geospatial applications 2 1 1 Raster Data One type of geospatial data is called raster data or simply a raster The most easily recognised form of raster data is digital satellite imagery or air photos Elevation shading or digital elevation models are also typically represented as raster data Any type of map feature can be represented as raster data but there are limitations A raster is a regular grid made up of cells or in the case of imagery pixels They have a fixed number of rows and columns Each cell has a numeric value and has a certain geographic size e g 30x30 metres in size Multiple overlapping rasters are used to represent images using more than one colour value i e one raster for each set of red green and blue values is combined to create a colour image Satellite imagery also represents data in multiple bands Each band is essentially a separate spatially overlapping aster where each band holds values of certain wavelengths of light As you an imagine a large raster takes up more file space A raster with smaller cells can provide more detail but takes up more file space The trick is finding the right balance between cell size for storage purposes and cell size for analytical or mapping purposes QGISO 8UserGuidesi i sSsSSSSS 2 1
78. ls 107 display results 58 edit permissions 57 loading data query builder 35 region 67 display 57 editing 57 snapping tolerance 55 starting QGIS 53 symbology settings 56 table editing 56l toolbox 57 Browser 58 customize modules 57 topology 53 vector data model 53 identify WMS 46 installation 6 layer visibility layers initial visibility 3 layout toolbars 10 legend 11 license exception 97 GPL B6 main window 8 map overview 1 view 1 MapInfo MIF files 78 TAB files 8 measure measure areas 14 measure line length 14 menus 9 MIF files 3 OGC coordinate reference system 45 CRS 45 introduction 42 WMS client 42 OGR 8 query builder B5 supported formats plugin Georeferencer 68 plugins 66 copyright 68 core delimited text external 68 geoprocessing 68 gps 63 graticule 68 installing 66 manager 66 managing 66 north arrow 68 scalebar 68 SPIT 68 template 69 types 66 plugins settings 68 PostGIS 8 49 Exporting 23 layers 21 query builder 85 spatial index 24 GIST 24 SPIT 24 QGIS 0 8 User Guide Index editing field names 24 importing data 23 loading 24 reserved words 24 PostgreSQL connection 21 testing 21 connection manager 21 connection parameters 22 database 22 host 22 layer deta
79. m that GPX file Each feature type will be loaded in a separate layer when you click OK 10 2 3 GPSBabel Since QGIS uses GPX files you need a way to convert other GPS file formats to GPX This can be done for many formats using the free program GPSBabel which is available at This program can also transfer GPS data between your computer and a GPS device QGIS uses GPSBabel to do these things so it is recommended that you install it However if you just want to load GPS data from GPX files you will not need it Version 1 2 3 of GPSBabel is known to work with QGIS but you should be able to use later versions without any problems 10 2 4 Importing GPS data To import GPS data from a file that is not a GPX file you use the tool mport other file in the GPS Tools dialog Here you select the file that you want to import which feature type you want to import from it where you want to store the converted GPX file and what the name of the new layer should be When you select the file to import you must also select the format of that file by using the menu in the file selection dialog see figure BT All formats do not support all three feature types so for many formats you will only be able to choose between one or two types 10 2 5 Downloading GPS data from a device QGIS can use GPSBabel to download data from a GPS device directly into vector layers For this you use the tool Download from GPS see Figure 22 where you select your type of
80. n a specified field Unique value objects are classified by the unique values within a specified field with each value having a different symbol To change the symbology for a layer simply double click on its legend entry and the vector layer properties dialog will be shown Figure 5 Vector Layer Properties Dialog Symbology General Metadata Labels Actions Legend type Single Symbol 7 Transparency 0 babe OS Point Symbol lo Outline Style Outline color Outline Width Fill Color Fill Patterns 4 3 2 Vector transparency QGIS 0 8 allows to set a transparency for every vector layer This can be done with the slider right below the legend type see fig B This is very useful for displaying several vector layers QGIS 0 8 User Guide 26 4 4 Attribute Actions 4 4 Attribute Actions QGIS provides the ability to perform an action based on the attributes of a feature This can be used to perform any number of actions for example running a program with arguments built from the attributes of a feature or passing parameters to a web reporting tool Actions are useful when you frequently want to run an external application or view a web page based on one or more values in your vector layer An example is performing a search based on an attribute value This concept is used in the following
81. n the desktop Under MS Windows start QGIS using the Start menu shortcut and under Mac OS X double click the icon in your Applications folder 3 3 1 Command Line Options QGIS supports a number of options when started from the command line To get a list of the options enter qgis help on the command line The usage statement for QGIS is holl bim gt qgis help Quantum GIS 0 8 0 TITAN Quantum GIS QGIS is a viewer for spatial data sets including raster and vector data Usage qgis options FILES QGIS 0 8 User Guide 6 3 3 Starting QGIS options snapshot filename emit snapshot of loaded datasets to given file lang language use language for interface text project projectfile load the given QGIS project extent xmin ymin xmax ymax set initial map extent help this text FILES Files specified on the command line can include rasters vectors and QGIS project files qgs 1 Rasters Supported formats include GeoTiff DEM and others supported by GDAL 2 Vectors Supported formats include ESRI Shapefiles and others supported by OGR and PostgreSQL layers using the PostGIS extension Tip 1 EXAMPLE USING COMMAND LINE ARGUMENTS You can start QGIS by specifying one or more data files on the command line For example assuming you are in your data directory you could start QGIS with two shapefiles and a raster file set to load on startup using the following command qgis ak_shade tif alaska shp ma
82. name and Delete buttons are only available in your current mapset All other tools also work on maps from other mapsets as well 8 6 3 Customizing the modules section Nearly all GRASS modules can be adopted to the GRASS toolbox A XML interface is provided to parse the very simple XML files which configure the modules inside the toolbox A brief description of adding new modules changing the modules group etc can be found on the QGIS wiki athttp wiki qgis org qgiswiki Adding_New_Tools_to_the_GRASS_Toolbox A sample XML file for generating the module v buffer v buffer qgm looks like this lt xml version 1 0 encoding UTF 8 gt lt DOCTYPE qgisgrassmodule SYSTEM http mrcc com qgisgrassmodule dtd gt lt qgisgrassmodule label Vector buffer module v buffer gt lt option key input typeoption type layeroption layer gt lt option key buffer gt lt option key output gt lt qgisgrassmodule gt The parser reads this definition and creates a new tab inside the toolbox when you select the module QGIS 0 8 User Guide 59 8 7 Creating new vectors Figure 15 GRASS toolbox GRASS Tools world _Il holl Moduls Browser BZ r R iol Moduls Browser B B Proll Raster bluemarble_ng GRASS gt g list rast B f raster bluemarble_ng E naturakearth_0o1 Columns 2968 E naturakarth_1 N S 0 0166667 region resolution raster fies available in mapset PERMANENT vector E W 0 0166667
83. ne string is multiple lines connected together 3 Polygons When lines are strung together by more than two points with the last point being at the same location as the first we call this a polygon A triangle circle rectangle etc are all polygons The key feature of polygons is that there is a fixed area within them QGIS 0 8 User Guide 5 3 Getting Started This chapter gives you a quick overview of running QGIS and examining data available on the QGIS web page 3 1 Installation Installation of QGIS is documented in Appendix 8 1 The Installation Guide is distributed with the QGIS source code and is also available at http qgis org Under Windows and Mac OS X QGIS is available as a standard installer package Packages for many flavors of Linux are also available Check the QGIS website at http qgis org for the latest information on binary packages 3 2 Sample Data If you do not have any GIS data handy you can obtain an Alaska dataset from the QGIS web site at http qgis org For use with GRASS a sample GRASS database Spearfish can be obtained from the official GRASS GlS website http grass itc it download data php These data sets will be used as the basis for many of the examples and screenshots provided in this document 3 3 Starting QGIS Assuming that QGIS is installed in the PATH you can start QGIS by typing qgis at a command prompt or by double clicking on the QGIS application link or shortcut o
84. ng the action on each one opening the output file will show something like this Acacia mearnsii 34 0800000000 150 0800000000 Acacia mearnsii 34 9000000000 150 1200000000 Acacia mearnsii 35 2200000000 149 9300000000 Acacia mearnsii 32 2700000000 150 4100000000 4 5 Editing QGIS supports basic capabilities for editing spatial data Before reading any further you should note that at this stage editing support is still preliminary Before performing any edits always make a backup of the dataset you are about to edit Note the procedure for editing GRASS layers is different see Section 8 4 for details 4 5 1 Editing an Existing Layer By default QGIS loads layers read only This is a safeguard to avoid accidentally editing a layer if there is a slip of the mouse However you can choose to edit any layer as long as the data provider supports it and the underlying data source is writable i e its files are not read only Layer editing is most versatile when used on PostgreSQL PostGIS data sources QGIS 0 8 User Guide 28 4 5 Editing Tip 9 DATA INTEGRITY Please consider backing up your data source before you start editing and also at regular intervals during editing QGIS is still at a pre version 1 0 stage and so may not be able to protect your data in all situations All editing sessions start by choosing the Allow editing option This can be found in the context menu after right clicking on the legend entry for that l
85. ng the menu option File gt Save Project Loading saved projects is a similar process The kinds of information saved in a project file include e Layers added e Layer properties including symbolization e Projection for the map view e Last viewed extent The project file is saved in XML format so it is possible to edit the file outside QGIS if you know what you are doing The file format is new in version 0 8 compared to earlier QGIS versions 3 8 GUI Options Some basic options for QGIS can be selected using the Options dialog Select the Settings entry from the menu and choose Options Alt O Some of the options you can customize are e Appearance e Rendering e Selection and Measuring e Projection e Help Browser Modify them according to your needs Some of the changes may require a restart of QGIS before they will be effective On GNU Linux everything is saved in QGIS 0 8 User Guide 15 3 9 Spatial Bookmarks HOME config QuantumGIS qgis conf This is a normal text file consisting of blocks where QGIS saves its current display options PostGIS and WMS connections and other settings On Windows settings are stored in the registry under HKEY_CURRENT_USER Software QuantumGIS qgis On OS X you can find your settings in HOME Library Preferences org qgis qgis plist 3 9 Spatial Bookmarks Spatial Bookmarks allow you to bookmark a geographic location and return to it later 3 9 1 Creating a Boo
86. nglists QGIS is still under active development and as such it won t always work like you expect it to The preferred way to get help is by joining the qgis users mailing list qgis users Your questions will reach a broader audience and answers will benefit others You can subscribe to the qgis users mailing list by visiting the following URL http lists qgis org cgi bin mailman listinfo qgis user qgis developer If you are a developer facing problems of a more technical nature you may want to join the qgis developer mailing list here http lists qgis org cgi bin mailman listinfo qgis developer qgis commit Each time a commit is made to the QGIS code repository an email is posted to this list If you want to be up to date with every change to the current code base you can subscribe to this list at http lists qgis org cgi bin mailman listinfo qgis commit qgis trac This list provides email notification related to project management including bug reports tasks and feature requests You can subscribe to this list at http lists qgis org cgi bin mailman listinfo qgis trac qgis doc This list deals with topics like documentation context help user guide and translation efforts If you like to work on the user guide as well this list is a good starting point to ask your questions You can subscribe to this list at http lists qgis org cgi bin mailman listinfo qgis doc qgis psc This list is used to
87. oduction is the most easily understood function of geospatial applications Mapping programs take geospatial data and render it in a form that is viewable usually on a computer screen or printed page Applications can present static maps a simple image or dynamic maps that are customised by the person viewing the map through a desktop program or a web page Many people mistakenly assume that geospatial applications just produce maps but geospatial data analysis is another primary function of geospatial applications Some typical types of analysis include computing 1 distances between geographic locations 2 the amount of area e g square metres within a certain geographic region 3 what geographic features overlap other features 4 the amount of overlap between features 5 the number of locations within a certain distance of another 6 and so on These may seem simplistic but can be applied in all sorts of ways across many disciplines The results of analysis may be shown on a map but are often tabulated into a report to support management decisions The recent phenomena of location based services promises to introduce all sorts of other features but many will be based on a combination of maps and analysis For example you have a cell phone that tracks your geographic location If you have the right software your phone can tell you what kind of restaurants are within walking distance While this is a novel application of geospa
88. odules it contains plus any associated interface definition files plus the scripts used to control compilation and installation of the executable However as a special exception the source code distributed need not include anything that is normally distributed in either source or binary form with the major components compiler kernel and so on of the operating system on which the executable runs unless that component itself accompanies the executable If distribution of executable or object code is made by offering access to copy from a designated place then offering equivalent access to copy the source code from the same place counts as distribution of the source code even though third parties are not compelled to copy the source along with the object code 4 You may not copy modify sublicense or distribute the Program except as expressly provided under this License Any attempt otherwise to copy modify sublicense or distribute the Program is void and will automatically terminate your rights under this License However parties who have received copies or rights from you under this License will not have their licenses terminated so long as such parties remain in full compliance 5 You are not required to accept this License since you have not signed it However nothing else grants you permission to modify or distribute the Program or its derivative works These actions are prohibited by law if you do not accept this License Ther
89. of QGIS double click to expand and mount the image then drag QGIS application to your hard drive If you want to build from source on Mac OS X seelhttp wiki qgis org qgiswiki BuildingOnMacOsX Installing the compressed disk image is the easiest method and gives you the full functionality of QGIS and all plugins including GRASS See the README file included on the disk image for additional instructions Additional information about the latest QGIS and its build relates can be found at http mrcc com wiki index php Building_QGIS_on_0S_X as well QGIS 0 8 User Guide 92 C 4 Building from Source C 4 Building from Source The remainder of this document deals with compiling and installing QGIS from source code Specifically this applies to GNU Linux and Unix systems At QGIS 0 8 there are two new requirements SQLite3 and Proj 4 These must be built and installed prior to configuring QGIS QGIS can be installed with four levels of support for data stores 1 Basic raster and vector support GDAL and OGR formats 2 PostreSQL GEOS PostGIS 3 GRASS raster and vector support 4 OGC WMS support Basic support uses the GDAL OGR libraries and supports many raster and vector formats For more information on the available formats see http gdal maptools org formats_list html and http gdal maptools org ogr ogr_formats html PostgreSQL PostGIS support allows you to store spatial data in a PostgreSQL database GRASS support provide
90. of type allows you to preselect some OGR supported file formats QGIS 0 8 User Guide 18 4 1 ESRI Shapefiles You can also select the Encoding type for the shapefile if desired Figure 3 Open OGR Data Source Dialog Look in thomesholltqgis_data Mi Zz fa ss qgis_data alaska shp canada shp lakes shp majrivers shp russia shp File name alaska shp Files of type LOGR ESRI Shapefiles shp SHP X Cancel Encoding S0 8859 15 gt Selecting a shapefile from the list and clicking OK loads it into QGIS Figure 4 shows QGIS after loading the country shp file Tip 4 LAYER COLORS When you add a layer to the map it is assigned a random color When adding more than one layer at a time different colors are assigned to each Once loaded you can zoom around the shapefile using the map navigation tools To change the symbology of a layer open the layer properties dialog by double clicking on the layer name or by right clicking on the name in the legend and choosing Properties from the popup menu See Section 4 3 T for more information on setting symbology of vector layers 4 1 2 Improving Performance To improve the performance of drawing a shapefile you can create a spatial index A spatial index will improve the speed of both zooming and panning Spatial indexes used by QGIS have a gix extension Use these steps to create the index QGIS 0 8 User Guide 19 4 1 ESRI Shapef
91. om QGIS 0 74 To build and install Proj4 download the latest version from http proj maptools org untar the distribution and configure make make install QGIS 0 8 User Guide 95 E 2 GEOS E 2 GEOS Note As of version 0 6 GEOS is a requirement in order to build QGIS QGIS uses GEOS to properly fetch features from the the underlying datastore when doing an identify or select operation At the time of this writing QGIS 0 8 supports only GEOS 2 x x To install GEOS 1 Download GEOS source from http geos refractions net 2 Untar GEOS tar xzf geos 2 x x tar gz 3 Change to the GEOS source dir cd geos 2 x x 4 Follow the instructions in the GEOS README file to complete the installation Typically the install goes like this configure make sudo make install E 3 PostgreSQL QGIS uses the latest features of PostgreSQL For this reason version 8 x x or higher is recommended with QGIS version 0 8 If you choose to add PostgreSQL you must also install PostGIS see E Note The following steps are only necessary when you install PostgreSQL from sources Most GNU Linux distributions have included the steps below into their package systems 1 Download PostgreSQL source from www postgresql org 5 2 Extract the source tar xzf postgresql 8 x x tar gz 3 Change to the source directory cd postgresql 8 x x QGIS 0 8 User Guide 96 E 3 PostgreSQL 4 Configure PostgreSQL configure prefix us
92. ommands interactively when run you must cause it when started running for such interactive use in the most ordinary way to print or display an announcement including an appropriate copyright notice and a notice that there is no warranty or else saying that you provide a warranty and that users may redistribute the program under these conditions and telling the user how to view a copy of this License Exception if the Program itself is interactive but does not normally print such an announcement your work based on the Program is not required to print an announcement These requirements apply to the modified work as a whole If identifiable sections of that work are not derived from the Program and can be reasonably considered independent and separate works in themselves then this License and its terms do not apply to those sections when you distribute them as separate works But when you distribute the same sections as part of a whole which is a work based on the Program the distribution of the whole must be on the terms of this License whose permissions for other licensees extend to the entire whole and thus to each and every part regardless of who wrote it Thus it is not the intent of this section to claim rights or contest your rights to work written entirely by you rather the intent is to exercise the right to control the distribution of derivative or collective works based on the Program In addition mere aggregation of another
93. oose Properties from the context menu to open the raster properties dialog for the layer Figure 10 shows the properties dialog There are five tabs on the dialog Symbology General Metadata Pyramids and Histogram Figure 10 Raster Layers Properties Dialog Symbology Display Color Image O Grayscale Image Paletted Image Notes C Invert Color Map This image uses a fixed color palette You can remap these colors in diferent combinations e g Transparency e Red blue in image Green blue in image e Blue green in image Grayscale Image Gray Std Deviations Color Map QGIS 0 8 User Guide 38 5 4 Raster Properties 5 4 1 Symbology Tab QGIS supports three forms of raster layers e Single Band Grayscale Rasters e Palette Based RGB Rasters e Multiband RGB Rasters From these three basic layer types eight forms of symbolised raster display can be used e Single Band Grayscale e Single Band Pseudocolor e Paletted Grayscale where only the red green or blue component of the image is displayed e Paletted Pseudocolor where only the red green or blue component of the image is displayed but using a pseudocolor algorithm e Paletted RGB e Multiband Grayscale using only one of the bands to display the image e Multiband Pseudocolor using only one of the bands shown in pseudocolor e Multiband RGB using any combination of three bands QGIS can invert the colors in a given layer so that light colo
94. ploaded and QGIS 0 8 User Guide 73 10 2 Using the GPS Plugin out is replaced by the port name You can learn more about GPSBabel and it s available command line options at http www gpsbabel org Once you have created a new device type it will appear in the device lists for the download and upload tools QGIS 0 8 User Guide 74 10 3 Using the Delimited Text Plugin 10 3 Using the Delimited Text Plugin The Delimited Text plugin allows you to load a delimited text file as a layer in QGIS 10 3 1 Requirements To view a delimited text file as layer the text file must contain 1 A delimited header row of field names This must be the first line in the text file 2 The header row must contain an X and Y field These fields can have any name 3 The x and y coordinates must be specified as a number The coordinate system is not important An example of a valid text file might look like this name latdec longdec cel11 196 mile creek 61 89806 150 0775 tyonek d 1 nel 197 1 2 mile creek 61 89472 150 09972 tyonek d 1 nel a b mountain 59 52889 135 28333 skagway c 1 swl apw dam number 2 60 53 145 75167 cordova c 5 sw apw reservoir 60 53167 145 75333 cordova c 5 sw apw reservoir 60 53 145 75167 cordova c 5 sw aaron creek 56 37861 131 96556 bradfield canal b 6 aaron island 58 43778 134 81944 juneau b 3 nel aats bay 55 905 134 24639 craig d 7 Some items of note about the text file are 1 The example text
95. primary key or have a column with a unique constraint on it QGIS additionally requires that this column be of type int4 an integer of size 4 bytes If a table lacks these items the oid column will be used instead Performance will be improved if the column is indexed note that primary keys are automatically indexed in PostgreSQL If the PostgreSQL layer is a view the same requirements exist but views don t have primary keys or columns with unique constraints on them In this case QGIS will try to find a column in the view that is derived from a table column that is suitable If one cannot be found QGIS will not load the layer If this occurs the solution is to alter the view so that it does include a suitable column a type of int4 and either a primary key or with a unique constraint preferably indexed 4 2 4 Importing Data into PostgreSQL shp2pgsq Data can be imported into PostgreSQL using a number of methods PostGIS includes a utility called shp2pgsq that can be used to import shapefiles into a PostGIS enabled database For example to import a shapefile named lakes into a PostgreSQL database named gis_data use the following command shp2pgsql s 2964 lakes shp lakes_new psql gis_data This creates a new layer named lakes_new in the the gis_data database The new layer will have a spatial reference identifier SRID of 2964 See Chapter for more information on spatial reference systems and projections Tip 7 EXPORTING D
96. r canvas and customized to show only the desired layers To add a legend click on the Add Vector Legend button The legend will be placed on the composer canvas and you can move it where you like Click on the tems tab to customize the appearance of the legend including which layers are shown To add a scalebar to the composer click on the Add Scalebar button Use the tem tab to customize the segment size number of segments scalebar units size and font for the scalebar J You can add text labels to the composer by clicking on the Add New Label button Use the Item tab while the text is selected to customize the settings or change the default text Figure 18 shows the map composer after adding each type of map element 9 1 3 Other Features The map composer has navigation tools to zoom in and out To zoom in click the zoom in tool The map composer canvas will be scaled by a factor to 2 Use the scrollbars to adjust the view to the area of interest Zooming out works in a similar fashion If you find the view in an inconsistent state you can use the refresh button to redraw the map composer canvas 9 1 4 Creating Output The map composer allows you to print the map to a printer export to a PNG or export to SVG Each of these functions is available from the composer toolbar a To save the composer canvas as a templates click on the Save Template As button Browse to the directory you like and save a template to use it again
97. r in the status bar shows progress of rendering as each layer is drawn to the map view In some cases such as the gathering of statistics in raster layers the progress bar will be used to show the status of lengthy operations On the right side of the status bar is a small checkbox which can be used to temporarily prevent layers being rendered to the map view see Section 3 5 below At the far right of the status bar is a projector icon Clicking on this opens the projection properties for the current project 3 5 Rendering By default QGIS renders all visible layers whenever the map canvas must be refreshed The events that trigger a refresh of the map canvas include e Adding a layer e Panning or zooming e Resizing the QGIS window e Changing the visibility of a layer or layers QGIS allows you to control the rendering process in a number of ways 3 5 1 Scale Dependent Rendering Scale dependent rendering allows you to specify the minimum and maximum scales at which a layer will be visible To set scale dependency rendering open the properties dialog by double clicking on the layer in the legend On the General tab set the minimum and maximum scale values and then click on the Use scale dependent rendering checkbox QGIS 0 8 User Guide 12 3 5 Rendering You can determine the scale values by first Zooming to the level you want to use and noting the scale value in the QGIS status bar 3 5 2 Controlling Map Rendering Map rend
98. r local pgsql 5 Build make 6 Install make install 7 As root create the postgres user and setup the database following taken from PostgreSQL INSTALL file with modification Create the postgres user adduser postgres Create the directory for the PostgreSQL database mkdir usr local pgsql data Change ownership of the data directory to the postgres user chown postgres usr local pgsql data su to the postgres user or login as postgres su postgres Change to the PostgreSQL install directory cd usr local pgsql Initialize the database bin initdb D usr local pgsql data Start the PostgreSQL daemon bin pg_ctl start o i D usr local pgsql data 1 home postgres serverlog Create the test database bin createdb test 8 PostgreSQL should now be running Login as the postgres user or use su postgres You should be able to connect to the test database and execute a test query with the following commands QGIS 0 8 User Guide 97 E 4 PostGIS psql test select version version PostgreSQL 8 x x on i686 pc linux gnu compiled by GCC gcc GCC 3 3 1 SuSE Linux 1 row q 9 PostgreSQL install is done E 4 PostGIS Note You must edit the PostGIS Makefile and make sure that USE_GEOS 1 is set Also adjust GEOS_DIR to point to your GEOS installation directory 1 Download PostGIS source from http postgis refractions net 4 2 Untar PostGIS into the contrib subdirectory of the Postgr
99. r plugins text This section describes how to work with two common formats ESRI shapefiles and PostGIS layers Many of the features available in QGIS work the same regardless of the vector data source This is by design and includes the identify select labeling and attributes functions Working with GRASS vector data is described in chapter 8 4 1 ESRI Shapefiles ESRI Shapefile support is provided by a library of functions known as the OGR Simple Feature Library See Appendix A i for a list of all supported formats in OGR A shapefile actually consists of a minimum of three files e shp file containing the feature geometries e dbf file containing the attributes in dBase format e shx index file Ideally it comes with another file with a prj suffix This describes the projection information for the shapefile There can be more files belonging to a shapefile dataset To have a closer look at this we recommend the technical specification for the shapefile format This can be found at http www esri com library whitepapers pdfs shapefile pdf 4 1 1 Loading a Shapefile To load a shapefile start QGIS and click on the Add a vector layer toolbar button This same tool can be used to load any of the formats supported by the OGR library Clicking on the tool brings up a standard open file dialog Figure B which allows you to navigate the file system and load a shapefile or other supported data source The selection box File
100. r projected coordinate system QGIS 0 8 User Guide 52 8 GRASS While GRASS 2 is a full blown hybrid GIS it can be used to extend QGIS with the following new features SS e Add GRASS vector layers yd Add GRASS raster layers e aR GRASS Toolbox e Vv Vector layers digitizing Ei Changing the GRASS region 8 1 Starting QGIS with GRASS If you like to use GRASS features from within QGIS you need to load the GRASS plugin with the plugin manager After loading the plugin you can immediately load your GRASS datasets using the appropriate toolbar buttons for vector and raster data If you want to use the GRASS toolbox you need to add a GRASS mapset where GRASS will store the resulting datasets 8 2 Loading GRASS Data With the GRASS plugin loaded you can load vector or raster layer using the appropriate button on the toolbar Tip 26 GRASS DATA LOADING If you have problems loading data or QGIS terminates abnormally check to make sure you have loaded the GRASS plugin properly as described in Section 8 1 8 3 Vector Data Model It is important to understand the GRASS vector data model prior to digitizing In general GRASS uses a topological vector model This means that areas are not represented as closed polygons but by one or more boundaries A boundary between two adjacent areas is digitized only once and it is QGIS 0 8 User Guide 53 8 4 Digitizing and Editing Tools shared by both areas Boundaries must be
101. r toolbar button e Choose the connection from the drop down list and click Connect e Find the layer you wish to add in the list of available layers e Select it by clicking on it You can select multiple layers by holding down the shift key while clicking See Section 4 6 for information on using the PostgreSQL Query Builder to further define the layer e Click on the Add button to add the layer to the map Tip 6 POSTGIS LAYERS Normally a PostGIS layer is defined by an entry in the geometry_columns table From version 0 74 on QGIS can load layers that do not have an entry in the geometry_columns table This includes both tables and views Defining a spatial view provides a powerful means to visualize your data Refer to your PostgreSQL manual for information on creating views QGIS 0 8 User Guide 22 4 2 PostGIS Layers 4 2 3 Some details about PostgreSQL layers This section contains some details on how QGIS accesses PostgreSQL layers Most of the time QGIS should simply provide you with a list of database tables that can be loaded and load them on request However if you have trouble loading a PostgreSQL table into QGIS the information below may help you understand any QGIS messages and give you direction on changing the PostgreSQL table or view definition to allow QGIS to load it QGIS requires that PostgreSQL layers contain a column that can be used as a unique key for the layer For tables this usually means that the table needs a
102. rated Value csv e DODS OPeNDAP e ESRI Shapefile e FMEObjects Gateway e GML e IHO S 57 ENC e Mapinfo File e Microstation DGN e OGDI Vectors e ODBC e Oracle Spatial e PostgreSQL e SDTS e SQLite e UK NTF e U S Census TIGER Line e VRT Virtual Datasource 3QGIS implements its own PostgreSQL functions OGR should be built without PostgreSQL support QGIS 0 8 User Guide 83 A 2 GDAL Raster Formats A 2 GDAL Raster Formats At the date of this document the following formats are supported by the GDAL library Note that not all of these format may work in QGIS for various reasons For example some require external commercial libraries Only those formats that have been well tested will appear in the list of file types when loading a raster into QGIS Other untested formats can be loaded by selecting the All other files filter Formats known to work in QGIS are indicated in bold Arc Info ASCII Grid e Arc Info Binary Grid adf e Microsoft Windows Device Independent Bitmap bmp e BSB Nautical Chart Format kap e VTP Binary Terrain Format bt e CEOS Spot for instance e First Generation USGS DOQ doq e New Labelled USGS DOQ doq e Military Elevation Data dt0 dt1 e ERMapper Compressed Wavelets ecw e ESRI hdr Labelled e ENVI hdr Labelled Raster e Envisat Image Product n1 e EOSAT FAST Format e FITS fits e Graphics Interchange Format gif e GRASS Rasters e TIFF
103. ributed plugins 10 1 1 Finding and Installing a Plugin When you install QGIS all of the core plugins are included see chapter 10 1 4 Typically user contributed plugins are distributed in source form and require compiling For instructions on building and installing a user contributed plugin see the documentation included with the plugin 10 1 2 Managing Plugins Managing plugins consists of loading or unloading them from QGIS Loaded plugins are remembered when you exit the application and restored the next time you run QGIS To manage plugins open the Plugin Manager from the Tools menu The Plugin Manager displays all the available plugins and their status loaded or unloaded Figure 9 shows the Plugin Manager dialog Typically all QGIS plugins are installed in the same location This location is shown in the Plugin Directory text field You can tell QGIS to load plugins from another location by specifying a different directory Tip 31 CRASHING PLUGINS If you find that QGIS crashes on startup a plugin may be at fault You can stop all plugins from loading by editing your stored settings file see 8 8 for location Locate the plugins settings and change all the plugin values to false to prevent them from loading For example to prevent the Delimited text plugin from loading the entry in HOME config QuantumGIS qgis conf on Linux should look like this Add Delimited Text Layer false Do this for each plugin in the Plugins s
104. rs become dark and dark colors become light Use the Invert Color Map checkbox to enable disable this behavior QGIS has the ability to display each raster layer at varying transparency levels Use the transparency slider to indicate to what extent the underlying layers if any should be visible though the current raster layer QGIS can restrict the data displayed to only show cells whose values are within a given number of standard deviations of the mean for the layer This is useful when you have one or two cells with abnormally high values in a raster grid that are having a negative impact on the rendering of the raster This option is only available for pseudocolor images QGIS 0 8 User Guide 39 5 4 Raster Properties 5 4 2 General Tab The General tab displays basic information about the selected raster including the layer source and display name in the legend which can be modified This tab also shows a thumbnail of the layer its legend symbol and the palette Additionally scale dependent visability can be set in this tab You need to check the checkbox and set an appropriate scale where your data will be displayed in the map canvas Also the spatal reference system is printed here as a PROUJ 4 string This can be modified by hitting the Change button 5 4 3 Metadata Tab The Metadata tab displays a wealth of information about the raster layer including statistics about each band in the current raster layer Statistics
105. s access to GRASS mapsets and GRASS modules for doing analytic task with your geodata Note If you plan to build QGIS with GRASS support version 1 2 6 or higher of GDAL must be used Recommended is a version higher than 1 3 1 where GDAL and GDAL GRASS support for QGIS is separated into different files They are loaded at runtime from within the GDAL OGR library Each of the requirements are discussed below Note that the information given below is abstracted from the installation documentation for each of the libraries See the install information for each library to get detailed instructions In the documentation below the file names and versions used are examples If you are building QGIS without PostgreSQL or GRASS support skip to the section on Installing GDAL OGR D Getting QGIS QGIS is available in both source and package format from the official QGIS website http qgis org QGIS 0 8 User Guide 93 D 1 Binary packages In addition packages for many GNU Linux distributions are independently maintained in various locations See the Download section on http qgis org for the latest information on package locations Packages for most of the software libraries discussed below can be found for almost all GNU Linux distributions While it is possible to mix compiling from source and installing packages to meet the requirements for QGIS sometimes this becomes tricky Following the steps below will generally ensure a successful
106. s to the map composer click on the Add a new map button in toolbar Drag a rectangle on the composer canvas to add the map You can resize the map later by clicking on the Select move item button clicking on the map and dragging one of the handles in the corner of the map With the map selected you can also resize the map by specifying the width and height on the Item properties tab The map is linked to the QGIS map canvas If you change the view on the map canvas by zooming or panning you can update the map composer view by selecting the map in composer and clicking on the Set Extent button You can also change the composer view by specifying a map scale To set the view to a specific scale QGIS 0 8 User Guide 62 9 1 Using Map Composer Figure 17 Map Composer MainWindow lt gatlileo gt 1 Choose Scale calculate extent from the Set drop down box 2 Enter the scale denominator in the scale box 3 Press Enter QGIS 0 8 User Guide 63 9 1 Using Map Composer 9 1 2 Adding other Elements to the Composer Already existing QGIS templates can be used to easily load and adapt map layouts To open an existing template click on the Open Template button Choose a template and customize its appearance To adda logo north arrow or any kind of image to the composer click on the Add Image button The image will be placed on the composer canvas and you can move it where you like A legend can be added to the compose
107. ssfully finished at the end Manual This tab shows the help page of each GRASS module You can have a look at the manual page if you want to get a deeper knowledge about the purpose of the module You may have recognized that some modules have more options and parameters than given in the Options tab This is correct and done by design To keep the GUI simple as possible only the needed options and parameters are put in the Options tab But you can always use the GRASS shell to run the module with all its parameters Tip 30 DISPLAY RESULTS IMMEDIATELY If you want to display your calculation results immediately in your map canvas you can use View Output button at the bottom of the module tab 8 6 2 GRASS Browser A very nice feature is the newly added GRASS browser in QGIS 0 8 At figure 16 a you can see the current location with its mapsets The browser on the left allows you to browse through all you mapsets inside your selected location The right side of the browser window shows some meta information for the selected dataset e g resolution bounding box data source attribute table for vector data QGIS 0 8 User Guide 58 8 6 GRASS Toolbox The toolbar inside the browser tab gives you the following tools for the selected dataset e wu Add selected map to canvas Copy selected map e Rename selected map e Re Delete selected map e O Set current region to selected map Q Refresh browser window The Re
108. tall by running gdal config formats If you ve had problems during the installation refer to this manual where the whole process is described with some more detail http www gdal org gdal_building html Note In order to get GRASS support into QGIS you need to compile the GRASS plugins for GDAL and OGR as well Please see section E 8 for more details E 7 GRASS If you want QGIS to support GRASS vector and raster layers you must build GRASS prior to proceeding Follow the directions on the GRASS website carefully to at least version 6 0 x better version 6 x x from CVS Additional information and the build instructions can be found at http grass itc it The GRASS software is available for download at http grass itc it download index php E 8 gdal GRASS plugins To enable GRASS raster support in QGIS the GDAL plugin for GRASS needs to be built You need the header files from GRASS and GDAL OGR in order to build the plugins QGIS 0 8 User Guide 100 E 9 E 9 Qt4 Download the GDAL GRASS distribution from http www gdal org d1 3 You should use the latest version of GDAL GRASS if possible The minimum recommended version for use with QGIS 0 8 is 1 3 1 Untar the distribution tar xfvz path to gdal grass 1 3 x x tar gz Change to the gdal grass 1 3 x x subdirectory that was created by step 2 cd gdal grass 1 3 x x Configure GDAL GRASS configure with grass path to your GRASS installation
109. tallation To import a shapefile into PostGIS do the following ogr2ogr f PostgreSQL PG dbname postgis host myhost de user postgres password topsecret alaska shp This will import the shapefile alaska shp into the PostGIS database posigis using the user postgres with the password topsecret on host myhost de Note that OGR must be built against PostgreSQL to support PostGIS You can see this by typing ogrinfo formats grep i post 4 2 5 Improving Performance Retrieving features from a PostgreSQL database can be time consuming especially over a network You can improve the drawing performance of PostgreSQL layers by ensuring that a spatial index exists on each layer in the database PostGIS supports creation of a GIST Generalized Search Tree index to speed up spatial searches of the data The syntax for creating a GIST index is GIST index information is taken from the PostGIS documentation available at http postgis refractions net QGIS 0 8 User Guide 24 4 3 The Vector Properties Dialog CREATE INDEX indexname ON tablename USING GIST geometryfield GIST_GEOMETRY_OPS Note that for large tables creating the index can take a long time Once the index is created you should perform a VACUUM ANALYZE See the PostGIS documentation 4 for more information The following is an example of creating a GiST index gsherman madison current psql gis_data Welcome to psql 8 0 0 the PostgreSQL interactive terminal
110. text Make sure of this before pressing Ok otherwise you may find the error will be caught later when you try to save your changes Editing Vertices of a Feature New in v0 8 For both PostgreSQL PostGIS and shapefile based layers the verticies of features can be edited Verticies can be directly edited that is you don t have to choose which feature to edit before you can change its geometry In some cases several features may share the same vertex and so the following rules apply when the mouse is pressed down near map features e Lines The nearest line to the mouse position is used as the target feature Then for moving and deleting a vertex the nearest vertex on that line is the editing target e Polygons If the mouse is inside a polygon then it is the target feature otherwise the nearest polygon is used Then for moving and deleting a vertex the nearest vertex on that polygon is the editing target You will need to set the property Settings gt Project Properties gt General gt Snapping Tolerance to a number greater than zero Otherwise QGIS will not be able to tell which feature is being edited Adding Vertices of a Feature New in v0 8 You can add new verticies to a feature by using the Add Vertex icon on the toolbar Note it doesn t make sense to add more verticies to a Point feature In this version of QGIS verticies can only be added to an existing line segment of a line feature If you want to extend a line
111. the QGIS in memory state is preserved This allows you to adjust your edits and try again 4 5 2 Creating a New Layer To create a new layer for editing choose New Vector Layer from the Layer menu The New Vector Layer dialog will be displayed as shown in Figure Z Choose the type of layer point line or polygon Figure 7 Creating a New Vector Dialog Type Point Line O Polygon File Format ESRI Shapefile Attributes Add Remove Name Type ID Integer name String Note that QGIS does not yet support creation of 2 5D features i e features with X Y Z coordinates or measure features At this time only shapefiles can be created In a future version of QGIS creation of any OGR or PostgreSQL layer type will be supported Creation of GRASS layers is supported within the GRASS plugin Please refer to section 8 7 for more information on creating GRASS vector layers QGIS 0 8 User Guide 33 4 6 Query Builder To complete the creation of the new layer add the desired attributes by clicking on the Add button and specifying a name and type for the attribute Only real integer and string attributes are supported Once you are happy with the attributes click Ok and provide a name for the shapefile QGIS will automatically add a shp extension to the name you specify Once the layer has been created it will be added to the map and you can edit it in the s
112. this layer can be rendered with transparency This version of QGIS will always use transparency if this is Yes and the image encoding supports transparency Can Zoom In Whether or not this layer can be zoomed in by the server This version of QGIS assumes all WMS layers have this set to Yes Deficient layers may be rendered strangely Cascade Count WMS servers can act as a proxy to other WMS servers to get the raster data for a layer This entry shows how many times the request for this layer is forwarded to peer WMS servers for a result Fixed Width Fixed Height Whether or not this layer has fixed source pixel dimensions This version of QGIS assumes all WMS layers have this set to nothing Deficient layers may be rendered strangely WGS 84 Bounding Box The bounding box of the layer in WGS 84 coordinates Some WMS servers do not set this correctly e g UTM coordinates are used instead If this is the case then the initial view of this layer may be rendered with a very zoomed out appearance by QGIS The WMS webmaster should be informed of this error which they may know as the WMS XML elements LatLonBoundingBox EX_GeographicBoundingBox or the CRS 84 BoundingBox Available in CRS The projections that this layer can be rendered in by the WMS server These are listed in the WMS native format Available in style The image styles that this layer can be rendered in by the WMS server 6 2 6 WMS Cli
113. tial technology it is essentially doing geospatial data analysis and listing the results for you This chapter is by Tyler Mitchell http www oreillynet com pub wlg 7053 and used under the Creative Commons License Tyler is the author of Web Mapping Illustrated published by O Reilly 2005 QGIS 0 8 User Guide 3 2 1 Why is all this so new 2 1 Why is all this so new Well its not There are many new hardware devices that are enabling mobile geospatial services Many open source geospatial applications are also available but the existence of geospatially focused hardware and software is nothing new Global positioning system GPS receivers are becoming commonplace but have been used in various industries for more than a decade Likewise desktop mapping and analysis tools have also been a major commercial market primarily focused on industries such as natural resource management What is new is how the latest hardware and software is being applied and who is applying it Traditional users of mapping and analysis tools were highly trained GIS Analysts or digital mapping technicians trained to use CAD like tools Now the processing capabilities of home PC s and open source software packages have enabled an army of hobbyists professionals web developers etc to interact with geospatial data The learning curve has come down The costs have come down The amount of geospatial technology saturation has increased How is geospatia
114. to install the binary you will also need to download and unpack the source tree since QGIS needs the header files in order to compile To install GDAL OGR from source 1 Download the GDAL distribution from http www gdal org 3 You should use the latest version of GDAL if possible The minimum recommended version for use with QGIS 0 8 is 1 3 1 2 Untar the distribution tar xfvz path to gdal x x x tar gz 3 Change to the gdal x x x subdirectory that was created by step 2 cd gdal x x x 4 Configure GDAL configure Since GDAL OGR supports a lot of different formats you should check to website see 3 for other dependencies required by GDAL OGR It may possible that you need more libraries and its header files installed in order to get a specific format linked into GDAL OGR QGIS 0 8 User Guide 99 E 7 GRASS 5 Build and install GDAL make sudo make install 6 In order to run GDAL after installing it is necessary for the shared library to be findable This can often be accomplished by setting LD_LIBRARY_PATH to include usr local lib On Linux you can add usr local lib or whatever path you used for installing GDAL to etc Id so conf and run ldconfig as root afterwards 7 Make sure that gdal config found in the bin subdirectory where GDAL was installed is included in the PATH If necessary add the path to gdal config to the PATH environment variable export PATH path to gdal config PATH 8 Check the ins
115. to using it Some other Free Software Foundation software is covered by the GNU Library General Public License instead You can apply it to your programs too When we speak of free software we are referring to freedom not price Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software and charge for this service if you wish that you receive source code or can get it if you want it that you can change the software or use pieces of it in new free programs and that you know you can do these things To protect your rights we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights These restrictions translate to certain responsibilities for you if you distribute copies of the software or if you modify it For example if you distribute copies of such a program whether gratis or for a fee you must give the recipients all the rights that you have You must make sure that they too receive or can get the source code And you must show them these terms so they know their rights We protect your rights with two steps 1 copyright the software and 2 offer you this license which gives you legal permission to copy distribute and or modify the software Also for each author s protection and ours we want to make certain that everyone understands that there is no warranty for this free software If the software is modified by som
116. torials where the vector model is described more deeply See http grass itc it gdp manuals php for more information books and tutorials in several languages 8 4 Digitizing and Editing Tools WV The digitizing tools for GRASS vector layers are accessed using the Edit GRASS Vector Layer tool on the toolbar Make sure you have loaded a GRASS vector and it is the selected layer in the legend before clicking on the edit tool If you like to create a new GRASS vector you need to use the toolbar entry Plugins gt GRASS gt Create new GRASS vector layer Figure 14 shows the GRASS Edit dialog that is displayed when you click on the edit tool The tools and settings are discussed in the following sections 8 4 1 Toolbar Table 4 lists the digitizing tools provided by the GRASS plugin These correspond to the tool buttons in the toolbar s across the top of the dialog QGIS 0 8 User Guide 54 8 4 Digitizing and Editing Tools Figure 14 GRASS Edit Dialog Left New point 8 4 2 Category Tab This tab allows you to set the way in which the category will be assigned to each new feature and or assign a category to a feature e Mode what category should be attached to geometry Next not used next category not yet used in vector file Manual entry define the category in the Category entry field No category digitize geometry without entering any category e Category a number ID attached to digitized fe
117. tructions for building an external plugin can be found atinttp wiki qgis org qgiswiki StepByStepBuildinstructions Some external plugins may include instructions on building If so follow the instructions provided with the plugin rather than those provided in the wiki QGIS 0 8 User Guide 105 Literature Web References 1 GEOS http geos refractions net 2006 2 GRASS GIS 2006 3 OGR Software Suite 2006 4 PostGIS jnttp postgis refractions net 2006 5 PostgreSQL http www postgresql org 2006 6 QGIS Development Team 2006 7 Web Map Service 1 1 1 Implementation Specification jnttp portal opengeospatial org files artii 2002 8 Web Map Service 1 3 0 Implementation Specification http portal opengeospatial org files artit 2004 9 SQlite nEEp 7www sqlite org 2006 Index AA actions 27 defining 27 examples 27 using 28 Allow Editing 28 bookmarks 16 command line options 6 coordinate reference system 45 crashes 66 CRS 45 data sample 6 data providers 67 delimited text editing 28 an existing layer 28 copying features 32 creating a new layer 83 cutting features icons 29 pasting features 2 saving changes 83 snap B3 EPSG 49 ESRI shapefiles 18 GDAL supported formats GRASS 3 attribute linkage 54 attribute storage 54 category settings 55 digitizing 53 digitizing too
118. udes the Image encoding Layers Layer Styles and Projections Since this is a network operation the speed of the response depends on the quality of your network connection to the WMS server Your screen should now look a bit like Figure 1 which shows the response provided by the NASA JPL OnEarth WMS server Image Encoding The Image encoding section now lists the formats that are supported by both the client and server Choose one depending on your image accuracy requirements Tip 21 IMAGE ENCODING You will typically find that a WMS server offers you the choice of JPEG or PNG image encoding JPEG is a lossy compression format whereas PNG faithfully reproduces the raw raster data Use JPEG if you expect the WMS data to be photographic in nature and or you don t mind some loss in picture quality This trade off typically reduces by 5 times the data transfer requirement compared to PNG Use PNG if you want precise representations of the original data and you don t mind the increased data transfer requirements Layers The Layers section lists the layers available from the selected WMS server You may notice that some layers are expandible this means that the layer can be displayed in a choice of image styles You can select several layers at once but only one image style per layer When several layers are selected they will be combined at the WMS Server and transmitted to QGIS in one go QGIS 0 8 User Guide sss 6 2 WMS Client
119. uous SVG markers symbology single unique value and graduated Display raster data such as digital elevation models aerial photography or landsat imagery Change raster symbology grayscale pseudocolor and multiband RGB Export to Mapserver map file Digitizing support Map overview Plugins 1 2 Whats New in 0 8 As usual the new version 0 8 bring some very interesting features to you QGIS 0 8 User Guide WMS support Improved vector and attribute editing Improved measure tools with area measuring Attribute searching New legend structure Refactoring of API to allow the use of QGIS libraries in mapping applications Improved MapServer export tool Vector layer transparency and antialiasing GRASS support in all platforms Enhanced GRASS support and toolbox commands Enhanced vector editing including copy cut paste snapping and vertex editing Shapefile OGR layer editing 2 Introduction To GIS A Geographical Information System GIS is a collection of software that allows you to create visualise query and analyse geospatial data Geospatial data refers to information about the geographic location of an entity This often involves the use of a geographic coordinate like a latitude or longitude value Spatial data is another commonly used term as are geographic data GIS data map data location data coordinate data and spatial geometry data Applications using geospatial data perform a variety of functions Map pr
120. work not based on the Program with the Program or with a work based on the Program on a volume of a storage or distribution medium does not bring the other work under QGIS 0 8 User Guide 87 the scope of this License 3 You may copy and distribute the Program or a work based on it under Section 2 in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following a Accompany it with the complete corresponding machine readable source code which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange or b Accompany it with a written offer valid for at least three years to give any third party for a charge no more than your cost of physically performing source distribution a complete machine readable copy of the corresponding source code to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange or c Accompany it with the information you received as to the offer to distribute corresponding source code This alternative is allowed only for noncommercial distribution and only if you received the program in object code or executable form with such an offer in accord with Subsection b above The source code for a work means the preferred form of the work for making modifications to it For an executable work complete source code means all the source code for all m

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