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v.what.vect.1grass

NAME

v.what.vect - Uploads vector values at positions of vector points to the table.

KEYWORDS

vector, database, attribute table

SYNOPSIS

v.what.vect
v.what.vect help
v.what.vect vector=name [layer=integer] column=string qvector=name [qlayer=integer] qcolumn=string [dmax=float] [--verbose] [--quiet]

Parameters:

vector=name

Points vector map to modify

layer=integer

Layer in the vector to be modified
Default: 1

column=string

Column to be updated with the query result

qvector=name

Vector map to be queried

qlayer=integer

Layer of the query vector containing data
Default: 1

qcolumn=string

Column to be queried

dmax=float

Maximum query distance in map units
Default: 0.0

DESCRIPTION

v.what.vect transfers attributes from the qvector's map attribute table into the attribute table of points present in the vector map. The script is based on v.distance.

NOTES

The upload column, into which the query results are stored, must be present in the vector map. Use v.db.addcol to add one if needed.

Use dmax parameter to control query distance tolerance (how far points can be from qvector features). For more options, use v.distance instead.

In case of a multipoint input vector map, with several points having the same category number, it can happen, that the query result is NULL, if the same category number falls into different qvector polygons.

EXAMPLE

In this example, the 'archsites' point map in the Spearfish location is copied to the current mapset, a new attribute column is added and the owner names from the 'fields' polygon map are transferred to the 'myarchsites' map at points' locations:
g.copy vect=archsites,myarchsites
v.db.addcol myarchsites col="owner varchar(25)"
v.what.vect myarchsites qvect=fields column=owner qcolumn=label
# verification:
v.db.select myarchsites

SEE ALSO

v.db.addcol, v.db.select, v.distance, v.rast.stats, v.what.rast

AUTHOR

Markus Neteler

Last changed: $Date: 2008-08-03 20:06:32 +0200 (Sun, 03 Aug 2008) $

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