NAME

       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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