NAME

       r3.univar   -  Calculates  univariate  statistics from the non-null 3d cells of a raster3d
       map.

KEYWORDS

       raster3d, voxel, statistics

SYNOPSIS

       r3.univar
       r3.univar help
       r3.univar [-get] input=name  [zones=name]   [output=name]   [percentile=float[,float,...]]
       [fs=character]   [--verbose]  [--quiet]

   Flags:
       -g
           Print the stats in shell script style

       -e
           Calculate extended statistics

       -t
           Table output format instead of standard output format

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       input=name
           Name of input raster3d map

       zones=name
           3D Raster map used for zoning, must be of type CELL

       output=name
           Name for output file (if omitted or "-" output to stdout)

       percentile=float[,float,...]
           Percentile to calculate (requires extended statistics flag)
           Options: 0-100
           Default: 90

       fs=character
           Field separator
           Special characters: space, comma, tab
           Default: |

DESCRIPTION

       r3.univar  calculates  the  univariate  statistics  for  raster3d maps.  This includes the
       number of cells  counted,  minimum  and  maximum  cell  values,  range,  arithmetic  mean,
       population  variance,  standard  deviation,  and  coefficient of variation. Statistics are
       calculated separately for every category/zone found in the zones input map if  given.   If
       the -e extended statistics flag is given the 1st quartile, median, 3rd quartile, and given
       percentile are calculated.  If the -g flag is given the results are presented in a  format
       suitable  for use in a shell script.  If the -t flag is given the results are presented in
       tabular format with the given field separator. The table can immediately be converted to a
       vector  attribute  table  which  can  then be linked to a vector, e.g. the vector that was
       rasterized to create the zones input raster.

NOTES

       As with most GRASS raster3d modules, r3.univar operates on the voxel array defined by  the
       current  3d  region settings, not the original extent and resolution of the input map. See
       g.region.

       This module can use large amounts of system memory when the -e extended statistics flag is
       used  with  a very large region setting. If the region is too large the module should exit
       gracefully with a memory allocation error. Basic statistics can be  calculated  using  any
       size input region.

TODO

       mode, skewness, kurtosis

SEE ALSO

         g.region,  r.univar, r.average, r.median, r.mode, r.quantile, r.sum, r.series, r3.stats,
       v.rast.stats, r.statistics, v.univar

AUTHORS

       Soeren Gebbert
       Code is based on r.univar from
       Hamish Bowman, Otago University, New Zealand
       and Martin Landa
       Zonal loop by Markus Metz

       Last changed: $Date: 2012-08-14 02:11:23 -0700 (Tue, 14 Aug 2012) $

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       © 2003-2013 GRASS Development Team