#1130: Request for a v.count.points grass module
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Reporter: nikos
| Owner: grass-...@…
Type: enhancement
| Status: new
Priority: normal
| Milestone:
Component: Vector
| Version: unspecified
Keywords: count points in areas, v.count.points.sh, v.what.vect, v.distance
| Platform: Unspecified
Cpu: Unspecified
|
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Currently there is no dedicated grass module to return the number of
points that fall inside an area. Although there is a specific function to
check if points fall within an area [1], the task is performed indirectly
using v.what.vect [2] (which in turn is a wrapper to v.distance) in a
script (e.g. v.count.points.sh [3]). Indirect methods (such as the
previously mentioned script) work fine but take (impractically) too long
when using (very) large point and area vector maps.[[BR]]
Counting points is rather a common task within the framework of GIS.
Therefore, it probably makes sense to have a native (faster and easy to
use) grass module that returns the number of points within area(s) and
optionally carry over attributes from the area to the point map (like
v.what.vect) or/and vice versa. Potentially, such a module can replace
completely the v.what.vect script (?).[[BR]]
A discussion upon the subject is to be found in the grass-dev mailing list
[4].[[BR]]
[1]
http://grass.osgeo.org/programming7/vector_2Vlib_2area_8c.html#a20344aaee88bf684dccdd2071da0851d
[[BR]]
[2] http://svn.osgeo.org/grass/grass/trunk/scripts/v.what.vect/ [[BR]]
[3] http://wiki.iosa.it/dokuwiki/spatial_analysis:feature_count [[BR]]
[4] http://lists.osgeo.org/pipermail/grass-dev/2010-August/051471.html
[[BR]]
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Ticket URL: <http://trac.osgeo.org/grass/ticket/1130>
GRASS GIS <http://grass.osgeo.org>
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