v.what.1grass - Man Page

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: Monday Sep 09 08:49:17 2024

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