Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.
NAME
r.extract - Extracts specified categories of an integer input map.
KEYWORDS
raster,
extract,
extent,
category
SYNOPSIS
r.extract
r.extract --help
r.extract [-cs] input=name output=name cats=range [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags:
- -c
- Clip to minimum extent
- -s
- Output reclassified map instead of true map
- --overwrite
- Allow output files to overwrite existing files
- --help
- Print usage summary
- --verbose
- Verbose module output
- --quiet
- Quiet module output
- --ui
- Force launching GUI dialog
Parameters:
- input=name [required]
- Name of input raster map
- output=name [required]
- Name for output raster map
- cats=range [required]
- Category values
- Example: 1,3,7-9,13
This module extracts selected categories from an integer raster map
into a new raster, similarly to
v.extract
for vectors. The categories and color table are preserved.
The category values can be specified as:
- cat1,cat2,...
- cat1-cat3
- cat1-
- -cat1
- and their combination: -cat1,cat2,cat3-cat6
The extent of the new raster can be changed with flag -c
to fit the extent of the extracted data. When using flag -s
output raster is a reclassified input raster
(see r.reclass
for details).
This implementation supports only integer raster maps (type CELL).
The following examples are using the full North Carolina sample
dataset. We will extract certain zipcodes.
First print zipcodes raster info:
g.region raster=zipcodes -p
r.info zipcodes -rg
...
rows=1350
cols=1500
min=27511
max=27610
...
Now we extract 2 categories and automatically adjust the raster extent
to fit the extracted data.
r.extract input=zipcodes output=selected_zipcodes cats=27605,27601 -c
r.info selected_zipcodes -rg
...
rows=404
cols=377
min=27601
max=27605
...
r.reclass (used in this implementation)
v.extract (for extracting vector data)
Anna Petrasova,
NCSU GeoForAll LabSOURCE CODE
Available at:
r.extract source code
(history)
Latest change: Mon Jun 28 07:54:09 2021 in commit: 1cfc0af029a35a5d6c7dae5ca7204d0eb85dbc55
Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.
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GRASS Development Team,
GRASS GIS 7.8.8dev Reference Manual