Thanks Hamish. It seems only likely that such a routine would exist.
Here's the part where I need a little help though. It appears that
v.distance from=pnt to=area dmax=0 upload=cat column=areacat
will find and report the cat number of the polygon that points lie
within, and I can use that
Friends,
If I understand correctly (based on experience with my own data),
when GRASS calculates the topology for vector area data it doesn't
actually ensure that the centroid lies within the area it represents.
If the area is a torus, or at least hollow in a general way, then the
Dave Roberts wrote:
Friends,
If I understand correctly (based on experience with my own data), when
GRASS calculates the topology for vector area data it doesn't actually
ensure that the centroid lies within the area it represents. If the area is
a torus, or at least hollow in a general
Friends,
This is the second time in two days I have had to post an apology
and retraction for hasty questions. I apologize for testing everyone's
patience. Thanks Markus; I was composing this message when I saw your
post. I mistook a centroid of a polygon too small to plot at the
Dave Roberts wrote:
It does raise a question, however, of what the conditions are that cause
d.what.vect to return a feature type of Boundary rather than Area when
querying a map.
d.what.vect and v.what search for points and centroids first. If none
is found, they continue and search for
Thanks Markus!
I think it would indeed be handy if a switch was added to v.what and
d.what.vect in GRASS 7. In the meantime it might be handy to write a
v.pip command for GRASS 6. I have written a point-in-polygon routine
for other software (including R), but I would have to really study
Dave wrote:
I think it would indeed be handy if a switch
was added to v.what and
d.what.vect in GRASS 7. In the meantime it might be
handy to write a v.pip command for GRASS 6. I have
written a point-in-polygon routine for other software
(including R), but I would have to really study
