NAME

       r.resamp.stats  - Resamples raster map layers to a coarser grid using aggregation.

KEYWORDS

       raster, resample

SYNOPSIS

       r.resamp.stats
       r.resamp.stats help
       r.resamp.stats  [-nw] input=name output=name  [method=string]   [--overwrite]  [--verbose]
       [--quiet]

   Flags:
       -n
           Propagate NULLs

       -w
           Weight according to area (slower)

       --overwrite
           Allow output files to overwrite existing files

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       input=name
           Name of input raster map

       output=name
           Name for output raster map

       method=string
           Aggregation method
           Options: average,median,mode,minimum,maximum,quart1,quart3,perc90,sum,variance,stddev
           Default: average

DESCRIPTION

       r.resamp.stats fills a grid cell (raster) matrix with aggregated values generated  from  a
       set of input layer data points.

       Without the -w switch, the aggregate is computed over all of the input cells whose centers
       lie within the output cell.

       With the -w switch, the aggregate uses the values from all input cells which intersect the
       output cell, weighted according to the proportion of the source cell which lies inside the
       output cell. This is slower, but produces a more accurate result.

NOTES

       Resampling modules (r.resample, r.resamp.stats,  r.resamp.interp,  r.resamp.rst)  resample
       the map to match the current region settings.

       The  notion  of  weighting doesn't make any sense for the min and max aggregates. However,
       the -w flag still has significance in that, when  multiple  destination  cells  overlap  a
       source  cell,  the  source  cell  is included in the calculation of all of the destination
       cells.

EXAMPLE

       Resample elevation raster map to a lower resolution (from 6m to 20m; North Carolina sample
       dataset):
       g.region rast=el_D782_6m -p
       g.region res=20 -ap
       r.resamp.stats input=el_D782_6m output=el_D782_20m

SEE ALSO

       g.region, r.resample, r.resamp.rst r.resamp.interp

AUTHOR

       Glynn Clements

       Last changed: $Date: 2011-11-08 03:29:50 -0800 (Tue, 08 Nov 2011) $

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       © 2003-2013 GRASS Development Team