Hi Simon, I guess there are more than one possibilities to create centre points (centroids) for polygon elements: the first option that comes to my mind is using the sextante plugin. There is an option "create centroids" for polygon vector layers. x/y coordinates can be calculated within the "field calculator" in gvSIG with the two commands x() and y(). You could use the geoprocessing "spatial join" to add tabular information of a point layer to a polygon theme. Hope that helps && regards, Wolfgang
Am Dienstag, den 24.11.2009, 23:57 +1100 schrieb Simon Cropper (Botanicus Australia Pty Ltd): > Hi Everyone, > > Can someone tell me if gvSIG can be used to establish the centre point > of a polygon? > > ... and subsequently place the X and Y coordinates in fields in the > attribute table of the polygon shapefile? > > ... or alternatively create a point file representing the centrepoint > and be able to assign the XY values to that shapefile. > > What I regularly do in alternative programs (OpenJUMP, Kosmo, Sextante) > is create a point file showing the centrepoint of a set of polygons > (usually representing the sites I have surveyed) and then using ArcView > assign the XY coordinate of the points to the northing+easting fields. > Reproject into Lat-Long and repeat. These coordinates are used to report > the sites locations to government agencies. > > How would you do this in gvSIG? > > Can you use Jpython to do this? _______________________________________________ Gvsig_internacional mailing list [email protected] http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional
