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v.what(1grass) Grass 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:

-d

Print topological information (debugging)
-a

Print attribute information
-g

Print the stats in shell script style
-j

Print the stats in JSON
-m

Print multiple features if overlapping features are found
--help

Print usage summary
--verbose

Verbose module output
--quiet

Quiet module output
--ui

Force launching GUI dialog

Parameters:

map=name[,name,...] [required]

Name of vector map(s)
layer=string[,string,...]

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
type=string[,string,...]

Input feature type
Options: point, line, boundary, centroid, area, face, kernel
Default: point,line,area,face
coordinates=east,north [required]

Coordinates for query
’-’ for standard input
distance=float

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

Last changed: $Date: 2014-10-22 12:22:22 +0200 (Wed, 22 Oct 2014) $

SOURCE CODE

Available at: v.what source code (history)

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© 2003-2019 GRASS Development Team, GRASS GIS 7.6.0 Reference Manual

GRASS 7.6.0