TRD 05: Data Presentation techniques (Mapping) Quantum GIS ...

4.1 ESRI Shapefiles
You can also select the Encoding type for the shapefile if desired.
Figure 3: Open OGR Data Source Dialog
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
4.3.1 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 .qix
extension.
Use these steps to create the index:
QGIS 0.8 User Guide 19