Monday, March 21, 2011

Split an area polygon with gvSIG

gvSIG's data editing functions are among the best I have ever encountered in a free and open source GIS software application. One of the useful command is the Split command. Here is how it works.

  1. Start up gvSIG OADE 2010. Add in a polygon shape file layer, e.g. polygons.shp.

    The layer is displayed in the View.
  2. In the legend, click the polygon layer.

    The layer is selected.
  3. Select Layer | Start Editing.

    The legend name is highlighted in red and the command pane appears.
  4. Select Geometry | Select. Click on the polygon.

    The polygon fill color changes to red and the vertex handles appear.
  5. Select Geometry | Modify | Split.

    The prompt Insert first point appears in the Command pane.
  6. Click a few points to digitize the splitting line.

  7. To complete, type in e in the Command pane prompt. Press RETURN.

    The polygon is split.
  8. Select Layer | Stop editing.

    You are prompted to save the edits.
  9. Click Yes.

    The changes are saved.

No comments: