NAME¶
r.rescale - Rescales the range of category values in a raster map
layer.
KEYWORDS¶
raster, rescale
SYNOPSIS¶
r.rescale
r.rescale help
r.rescale [-
q]
input=
string
[
from=
min,max]
output=
string
to=
min,max [
title=
"phrase"]
[--
overwrite] [--
verbose] [--
quiet]
Flags:¶
- -q
-
Quietly
- --overwrite
-
Allow output files to overwrite existing files
- --verbose
-
Verbose module output
- --quiet
-
Quiet module output
Parameters:¶
- input=string
-
The name of the raster map to be rescaled
- from=min,max
-
The input data range to be rescaled (default: full range of input map)
- output=string
-
The resulting raster map name
- to=min,max
-
The output data range
- title=
-
Title for new raster map
DESCRIPTION¶
The
r.rescale program rescales the range of category values appearing in
a raster map layer. A new raster map layer, and an appropriate category file
and color table based upon the original raster map layer, are generated with
category labels that reflect the original category values that produced each
category. This command is useful for producing representations with a reduced
number of categories from a raster map layer with a large range of category
values (e.g., elevation).
Rescaled map layers are appropriate for use
in such GRASS programs as
r.stats,
r.report, and
r.coin.
EXAMPLE¶
To rescale an elevation raster map layer with category values ranging from 1090
meters to 1800 meters into the range 0-255, the following command line could
be used (without the
from parameter, the full value range will be
used):
r.rescale input=elevation from=1090,1800 output=elevation.255 to=0,255
NOTES¶
Category values that fall beyond the input range will become NULL. This allows
the user to select a subset of the full category value range for rescaling if
desired. This also means that the user should know the category value range
for the input raster map layer. The user can request the
r.rescale
program to determine this range, or can obtain it using the
r.info
command. If the category value range is determined using
r.rescale, the
input raster map layer is examined, and the minimum and maximum non-NULL
category values are selected as the input range.
SEE ALSO¶
r.coin,
r.describe,
r.info,
r.mapcalc,
r.reclass,
r.rescale.eq,
r.report,
r.resample,
r.stats
AUTHOR¶
Michael Shapiro, U.S.Army Construction Engineering Research Laboratory
Last changed: $Date: 2010-10-06 18:11:45 +0200 (Wed, 06 Oct 2010) $
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