[GRASS-user] polygons and centroids redux

[Dave Roberts]

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 the 
file structures of GRASS vectors to attempt that in GRASS.   If any 
GRASS programmers are interested let me know and perhaps we could work 
it out as an add-on.

Thanks, Dave R


Markus Metz wrote:
> 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 lines, boundaries and faces. If
> none is found, they continue and search for areas. This search order
> causes any centroid or boundary to be returned if found, and not the
> corresponding area. Currently there is no way to select the feature
> type (point, centroid, line, boundary, area, face) to be searched.
> This option could be added for v.what in 7.0 if desired.
> 
> Markus M
>