GRASS logo

NAME

r.quantile - Compute quantiles using two passes.

KEYWORDS

raster, algebra, statistics, percentile, quantile

SYNOPSIS

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

Flags:

-r
Generate recode rules based on quantile-defined intervals
--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
quantiles=integer
Number of quantiles
Default: 4
percentiles=float[,float,...]
List of percentiles
bins=integer
Number of bins to use
Default: 1000000
file=name
Name for output file (if omitted or "-" output to stdout)

Table of contents

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 13:17:36 -0800 (Fri, 19 Dec 2014) $

SOURCE CODE

Available at: r.quantile source code (history)


Main index | Raster index | Topics index | Keywords index | Graphical index | Full index

© 2003-2017 GRASS Development Team, GRASS GIS 7.5.svn Reference Manual