NAME

       r.quantile  - Compute quantiles using two passes.

KEYWORDS

       raster, statistics

SYNOPSIS

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

   Flags:
       -r
           Generate recode rules based on quantile-defined intervals.

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       input=name
           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 rast=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 rast=elevation -p
       r.quantile elevation quantiles=5 -r --quiet | r.recode elevation \
                  out=elev_quant5 rules=-

SEE ALSO

        r.quant

AUTHOR

       Glynn Clements

       Last changed: $Date: 2013-04-10 08:52:37 -0700 (Wed, 10 Apr 2013) $

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       © 2003-2013 GRASS Development Team