r.quantile.1grass man page

r.quantile — Compute quantiles using two passes.

Keywords

raster, algebra, statistics

Synopsis

r.quantile
r.quantile --help
r.quantile [-r] input=name [quantiles=integer] [percentiles=float[,float,...]] [bins=integer] [--help] [--verbose] [--quiet] [--ui]

Flags

-r
Generate recode rules based on quantile-defined intervals
--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
quantiles=integer
Number of quantiles
Default: 4
percentiles=float[,float,...]
List of percentiles
bins=integer
Number of bins to use
Default: 1000000

Description

r.quantile computes quantiles in a manner suitable for use with large amounts of data. It is using two passes.

Example

Calculation of elevation quantiles (printed to standard-out):

g.region raster=elevation -p
r.quantile input=elevation percentiles=0.1,1,10,25,50,75,90,99,99.9

The output of r.quantile can be used for quantile classification:

g.region raster=elevation -p
r.quantile elevation quantiles=5 -r --quiet | r.recode elevation \
           out=elev_quant5 rules=-

See Also

r.mode, r.quant, r.quantile, r.series, r.stats, r.stats.quantile, r.stats.zonal, r.statistics, r.univar, v.rast.stats

Author

Glynn Clements

Last changed: $Date: 2014-12-19 22:55:37 +0100 (Fri, 19 Dec 2014) $

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GRASS 7.0.4 Grass User's Manual