Why are “capture line” etc not available?

Question

I have a question about QGIS which I just started using. I loaded a shp file and want to edit different elements, but the tool for drawing a new line or adding new points does not appear. I can add a new polygon but not just a line it seems (for example I want to split a polygon by drawing a line) does anybody knows how I can find/use these tools.Thank you very much for the help.

Hendrik

Answer 1

It is not possible to mix different geometry types in one Shapefile. Instead, create three Shapefiles: one for point, one for line and one for polygons.

Answer 2

To split a polygon you probably want the 'Advanced Digitizing' toolbar. Right-click anywhere in your toolbars and a pop-up menu will appear. About half-way down you will find a check-box for Advanced Diogitizing. Click on that to turn it on. Once you have the toolbar you will find the split features tool.

To add points and lines, remember that a shapefile can only contain one type of geometry, which is why you can add polygons but not the other two. To create a new layer go to Layer->New Layer->New Shapefile Layer. Then you will be asked to specify the geometry type. Once you have a point or line file the Add Feature button in the Digitizing toolbar will add points or lines respectively.

Other tools you may find useful could include for this sort of work:

• Coordinate Capture
• Numerical Vertex Edit
• CAD Tools

There are loads of other plugins. These are just ones I use most often when editing vector data. To get these (and others) go to Plugins->Fetch Plugins. You can use Plugins->Manage Plugins to turn plugins on and off.