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v.what

Queries a vector map at given locations.

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

Example:

v.what map=name coordinates=east,north

grass.script.parse_command("v.what", map, layer="-1", type="point,line,area,face", coordinates, distance=0, columns=None, flags=None, verbose=False, quiet=False, superquiet=False)

Example:

gs.parse_command("v.what", map="name", coordinates=east,north)

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
    Allowed values: 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
-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
--qq
    Very quiet module output
--ui
    Force launching GUI dialog

map : str | list[str], required
    Name of vector map(s)
    Used as: input, vector, name
layer : str | list[str], optional
    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.
    Used as: input, layer
    Default: -1
type : str | list[str], optional
    Input feature type
    Allowed values: point, line, boundary, centroid, area, face, kernel
    Default: point,line,area,face
coordinates : tuple[float, float] | list[float] | str, required
    Coordinates for query
    '-' for standard input
    Used as: input, coords, east,north
distance : float, optional
    Query threshold distance
    Default: 0
columns : str | list[str], optional
    Name of attribute column(s)
    Default: all columns
    Used as: input, dbcolumn, name
flags : str, optional
    Allowed values: d, a, g, j, m
    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
verbose: bool, optional
    Verbose module output
    Default: False
quiet: bool, optional
    Quiet module output
    Default: False
superquiet: bool, optional
    Very quiet module output
    Default: False

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)
Latest change: Monday Mar 10 21:11:57 2025 in commit bd253b7