![]() ![]() To learn more about what is possible with pie chart diagram symbols, you can experiment with this recipe in the ScriptRunner plugin where you can change or remove settings and quickly re-render the map. The following screenshot shows an example of the completed pie chart diagram map. Fortunately most of them are self-explanatory. Most of the settings are poorly documented if at all. It turns out they are actually quite complex. However it gets a little confusing in that we must apply settings at three different levels: the diagram level, the render level, and the layer level. The basics of pie chart diagram symbols are straight forward and work similar to other types of symbols and renderers. Finally, add our diagram layer to the map:.Ifhasattr(lyr, “setCacheImage”): lyr.setCacheImage(None) Next we delete any cached images that are rendered and force the layer to repaint:.In QGIS 2.6, The diagram renderer is tied to the new PAL labeling engine so we need to activate that engine:.Now we apply some additional placement settings at the layer level:.And then we add the renderer to the layer:.Then we can add our diagram to the renderer:.We must set a few size parameters for our diagrams:.Now we can create our diagram renderer:ĭr = QgsLinearlyInterpolatedDiagramRenderer().Now we define all of the diagram settings that will be used for the renderer:ĭs.BackgroundColor = QColor(255,255,255,0).Then we create a diagram settings object:.Next we convert the hex color values to QColor objects:.Now we set up a list of corresponding colors for each category:Ĭolors =.Next we set up categories based on attribute names:Ĭategories =.Lyr = QgsVectorLayer(“/Users/joellawhead/qgis_data/ms/County10PopnHou.shp”, “Population”, “ogr”) The pie chart diagram renderers are more complex than other renderers with many more options. #Symbols quantum gis downloadIn this recipe we’ll use pie chart symbols on a polygon layer in QGIS.įor this recipe download the following zipped shapefile and extract it to a directory named ms in your qgis_data directory:Īs with other renderers, we will build a symbol layer add it to a renderer, and display the layer on the map. QGIS has the ability to use dynamic pie charts as symbols describing statistics in a given region. The following map image shows the recipe output. You can also add your own graphics as well. ![]() There are numerous graphics available covering many common uses. The default SVG layers are stored in the QGIS application directory. QgsMapLayerRegistry.instance().addMapLayer(lyr) Finally we add the layer to the map to view the SVG symbol:.Lyr.rendererV2().symbols().changeSymbolLayer(0, symLyr1) Now we change the layer renderer’s default symbol layer:.SymLyr1 = QgsSvgMarkerSymbolLayerV2.create(svgStyle) ![]()
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