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] [columns=name[,name,...]] [--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

columns=name[,name,...]
    Name of attribute column(s)
    Default: all columns

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)

Accessed: Thursday Oct 30 22:18:23 2025

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