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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.quantile.ref - Determines quantile for input value from reference raster map layers.

KEYWORDS

raster, aggregation, series, statistics, quantile

SYNOPSIS

r.quantile.ref
r.quantile.ref --help
r.quantile.ref [-z] input=name [reference=name[,name,...]] [file=name] output=name [range=lo,hi] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-z
Do not keep files open
--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
reference=name[,name,...]
List ofreference raster maps
file=name
Input file with one reference raster map name per line
output=name [required]
Name for output raster map
range=lo,hi
Ignore values outside this range

Table of contents

DESCRIPTION

r.quantile.ref computes for each pixel the quantile ranking of the input value against the reference maps: values of 0, 0.5 and 1.0 respectively indicate that the input value corresponds with the minimum, median or maximum of the reference values. A value of -1 is assigned if the input value is smaller than the minimum and a value of 2 is assigned if the input value is larger than the maximum.

r.quantile.ref can be regarded as the inverse of r.series method=quantile: while r.series calculates the value for a given quantile, r.quantile.ref calculates the quantile for a given value. This is useful to compare e.g. current environmental conditions to a time series of historical environmental conditions.

EXAMPLE

Create some reference rasters:
r.mapcalc "ref1 = 1"
r.mapcalc "ref2 = 2"
r.mapcalc "ref3 = 3"
r.mapcalc "ref4 = 5"
r.mapcalc "ref5 = 5"
r.mapcalc "ref6 = 5"
Create a test raster with cell value 4.5:
r.mapcalc "test = 4.5"
Get the quantile of the test raster for the reference maps:
r.quantile.ref input=test reference=ref1,ref2,ref3,ref4,ref5,ref6 output=test_quant
The quantile corresponding to the value 4.5 is 0.55. Create a test raster with cell value 5:
r.mapcalc "test = 5"
Get the quantile of the test raster for the reference maps:
r.quantile.ref input=test reference=ref1,ref2,ref3,ref4,ref5,ref6 output=test_quant
The quantile corresponding to the value 5 is 0.8.

SEE ALSO

r.quantile, r.series

AUTHOR

Markus Metz

SOURCE CODE

Available at: r.quantile.ref 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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© 2003-2022 GRASS Development Team, GRASS GIS 7.8.8dev Reference Manual