I have problems to use the function
v.what.vect and I'm not sure what is the issue. I have a simple forest polygon and try to determine if a point is in the forest or not.
# check the output of the feature nature v.db.select nature col=landuse where="cat<5" # function returns landuse forest forest forest forest # add column to points v.db.addcolumn map=points col="landuse varchar(50)" # use function v.what.vect v.what.vect map=points column=landuse query_map=nature query_column=landuse # function returns Finding nearest features ... 100% 100% Update vector attribute... 100% 2696 categories - no nearest feature found v.distance complete. 2696 records updated.
For me its looks like everything worked fine, just the that the result 0 is wired. Any idea what went wrong or how to check it?
I checked again the notes of the
In case of a multipoint input map map, with several points having the same category number, it can happen, that the query result is NULL, if the same category number falls into different query_map polygons.
But that is also given:
v.db.select points col=cat where="cat<5" # function output: cat 1 2 3 4 5