Monday, April 18, 2011

Join (or merge) polygons in gvSIG

Merging two or more polygons in gvSIG is simple to do. You have to make sure that the line work is topologically clean first i.e. no overlap and there must be coincident vertices. Otherwise, a compound geometry consisting of multiple polygons would be created instead.

The steps to join polygons are below:
  1. Start up gvSIG OADE 2010. Open a new View and add a polygon layer, e.g. polygons.shp.

  2. In the legend or table of contents, click on the polygons.shp layer name.

    The selected layer becomes the active layer.
  3. Select Layer | Start Editing.

    The legend name changes to red. The Command pane appears.
  4. Select Geometry | Select.
  5. Press CTRL and click on two or more polygons to join.

    The selected polygons fill color changes to red.
  6. Select Geometry | Modify | Join.

    The selected polygons are joined.
  7. Select Layer | Stop Editing.

    The prompt to save appears.
  8. Click Yes.

    The changes are saved.


-Jon HB said...

Is there a way to join multiple polygons with one specific attribute?

dominoc925 said...

Hi Commentator, yes there is a way to join multiple polygons with one attribute. It is through the gvSIG geoprocessing tools. An example is here: