NAME
v.what - Queries a vector map at given locations.
KEYWORDS
vector,
querying,
position
SYNOPSIS
v.what
v.what --help
v.what [-aidgjm] map=name[,name,...] [layer=string[,string,...]] [type=string[,string,...]] coordinates=east,north [distance=float] [columns=name[,name,...]] [format=name] [--help] [--verbose] [--quiet] [--ui]
Flags:
- -a
- Print attribute information
- -i
- Print attribute database connection information
- -d
- Print topological information (debugging)
- Prints internal information for topology debugging
- -g
- Print the stats in shell script style [deprecated]
- This flag is deprecated and will be removed in a future release. Use format=shell instead.
- -j
- Print the stats in JSON [deprecated]
- This flag is deprecated and will be removed in a future release. Use format=json instead.
- -m
- Print multiple features for each map if they meet the criteria
- For JSON, this places features under a "features" key
- --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
- format=name
- Output format
- Options: plain, shell, json
- plain: Plain text output
- shell: shell script style output
- json: JSON (JavaScript Object Notation)
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.
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
d.what.rast,
d.what.vect,
v.rast.stats,
v.vect.stats,
v.what.rast,
v.what.rast3,
v.what.vect
Trevor Wiens
Edmonton, Alberta, Canada
SOURCE CODE
Available at:
v.what source code
(history)
Latest change: Thursday Sep 04 02:30:01 2025 in commit: 33644dd226ea800453da0c963e25fb41cf5ba60d
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© 2003-2025
GRASS Development Team,
GRASS 8.5.0dev Reference Manual