DESCRIPTION

v.select allows the user to select features from a vector by features from another one.

NOTES

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 map: 
v.select ainput=fire binput=forest output=forest_fire

Extract Italian rivers from VMAP0 watercourses map: 

v.select ainput=watrcrsl_eurnasia_wgs84 binput=italy_area \
         output=watrcrsl_italy operator=overlap

SEE ALSO

v.category, v.overlay, GRASS SQL interface

AUTHORS

Radim Blazek

Last changed: $Date$