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v.what(1grass) GRASS GIS User's Manual v.what(1grass)

NAME

v.what - Queries a vector map at given locations.

KEYWORDS

vector, querying, position

SYNOPSIS

v.what
v.what --help
v.what [-dagjm] map=name[,name,...] [layer=string[,string,...]] [type=string[,string,...]] coordinates=east,north [distance=float] [--help] [--verbose] [--quiet] [--ui]

Flags:


Print topological information (debugging)

Print attribute information

Print the stats in shell script style

Print the stats in JSON

Print multiple features if overlapping features are found

Print usage summary

Verbose module output

Quiet module output

Force launching GUI dialog

Parameters:


Name of vector map(s)

Layer number or name (’-1’ for all layers)
A single vector map can be connected to multiple database tables. This number determines which table to use. When used with direct OGR access this is the layer name.
Default: -1

Input feature type
Options: point, line, boundary, centroid, area, face, kernel
Default: point,line,area,face

Coordinates for query
’-’ for standard input

Query threshold distance
Default: 0

DESCRIPTION

v.what outputs the category number value(s) associated with user-specified location(s) in user-specified vector map layer(s). This module was derived from the d.what.vect module by removing all interactive code and modification of the output for easy parsing. Using the -g flag generates script-style output which is easily parsable.

EXAMPLE

North Carolina sample dataset example:

Query polygon at given position:

v.what zipcodes_wake coordinates=637502.25,221744.25

Find closest hospital to given position within given distance (search radius):

v.what hospitals coordinates=542690.4,204802.7 distance=2000000

SEE ALSO

d.what.rast, d.what.vect, v.rast.stats, v.vect.stats, v.what.rast, v.what.rast3, v.what.vect

AUTHOR

Trevor Wiens
Edmonton, Alberta, Canada

SOURCE CODE

Available at: v.what source code (history)

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© 2003-2021 GRASS Development Team, GRASS GIS 7.8.6 Reference Manual

GRASS 7.8.6