Exporting multiple layers to single dxf file using Grass GIS?

Question

I'm very new to Grass GIS.

I need to export multiple vector layers into a single dxf file (required in order to import into another application).

However, I can't see a way of selecting more than one layer at the same time for export to a single dxf.

Is this actually possible in Grass GIS?

Answer 1

Patch (merge) the two vector maps together (I'm using roadsmajor and streams from the North Carolina sample dataset for GRASS GIS):

v.patch input=roadsmajor,streams output=roads_and_streams

Export using GDAL/OGR:

v.out.ogr input=roads_and_streams format=DXF output=roads_and_streams1.dxf

Alternatively, export using specialized module:

v.out.dxf i=roads_and_streams o=roads_and_streams2.dxf

Just for checking the resulting geometries, I imported both files back to GRASS GIS using always the other complimentary tool (v.in.dxf for v.out.ogr output and v.in.ogr for v.out.dxf output).

To do this in GUI, just use the (Command) Console tab, paste the name of the module (e.g. v.patch), press Enter, and fill the dialog.