[GRASS-user] retrieve centroids from polygons

[Moritz Lennert]

On 01/12/08 14:57, Niels Thevs wrote:
> Hi,
> 
> how can I extract the centroids from polygons and transform them into a 
> point vector layer ? I have tiny polygons as groundtruth data for a 
> satellite image analysis and I would like to retrieve the centroids as 
> points so that I can use v.what.rast, in order to obtain the spectral 
> information for the groundtruth data.

v.extract in=map_polygons type=centroid out=map_centroids
v.type in=map_centroids out=map_points type=centroid,point

Moritz