Hi Dave,
what I did in this case, was, as you said, to convert the centroids to
points and then run v.what.rast.
One possibility to get the information to your table:
1- Convert the polygons (the categories) to raster with r.to.vect.
2- Do a v.what.rast with this "raster-area" map.
3- Make a table update and use 2- for identifying the right items.
I hope you like it,
Achim
Am 10.06.2010 19:40, schrieb Dave Roberts:
Friends,
I have an vector area map with numerous polygons with centroids. When I do
v.what.rast vector=A raster=B column=C
It appears to run, but doesn't actually enter any data into column C in
the associated table in Postgres. Reading the help file, I suspect this
is because A is an area instead of a point map, but the areas do have
centroids which I would expect v.what.rast to employ.
I could import the centroids as a separate points map, but then they're
not associated with the table in Postgres.
What's considered best practices in associating polygon centroids with
other rasters or vector areas?
Thanks, Dave
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