other versions
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v.select(1grass) | Grass User's Manual | v.select(1grass) |
NAME¶
v.select - Selects features from vector map (A) by features from other vector map (B).KEYWORDS¶
vector, spatial querySYNOPSIS¶
v.selectFlags:¶
- -t
-
- -c
-
- -r
-
- --overwrite
-
- --verbose
-
- --quiet
-
Parameters:¶
- ainput=name
-
- atype=string[,string,...]
-
- alayer=integer
-
- binput=name
-
- btype=string[,string,...]
-
- blayer=integer
-
- output=name
-
- operator=string
-
DESCRIPTION¶
v.select allows the user to select features from a vector map by features from another one. Supported operators (without GEOS): overlap - features partially or completely overlap Supported operators (with GEOS): equals - features are spatially equals disjoint - features do not spatially intersect intersects - features spatially intersect touches - features spatially touches crosses - features spatially crosses within - feature A is completely inside feature B contains - feature B is completely inside feature A overlaps - features spatially overlap relate - feature A is spatially related to feature BNOTES¶
Only features with category numbers will be considered. If required the v.category module can be used to add them. Typically boundaries do not need to be given a category number, as an area's attributes are inherited from the centroid. Typically points, lines, and centroids will always want to have a cat number. E.g. take a road which separates two farms. It is ambiguous as to which farm an attribute that is attached to the road belongs to. The boundary only needs a cat number if it will hold its own attributes, such as road name or pavement form. A centroid in each paddock holds the information with respect to ownership, area, etc.EXAMPLES¶
Extract forest fire points from larger fire vector map:output=watrcrsl_italy operator=overlap
TODO¶
Processing areas with GEOS is currently incredibly slow. Significant speed-up is required.SEE ALSO¶
v.category, v.overlay GRASS SQL interfaceAUTHORS¶
Radim BlazekGRASS 6.4.2 |