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]     [quantile=float]
       [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       -n
           Propagate NULLs

       -w
           Weight according to area (slower)

       --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

       output=name [required]
           Name for output raster map

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

       quantile=float
           Quantile to calculate for method=quantile
           Options: 0.0-1.0
           Default: 0.5

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 raster=el_D782_6m -p
       g.region res=20 -ap
       # from 6m to 20m: weighted resampling -w
       r.resamp.stats -w input=el_D782_6m output=el_D782_20m
       Resampling of 6m DEM (left) to 20m DEM (right) with weighted resampling (subset)

SEE ALSO

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

       Overview: Interpolation and Resampling in GRASS GIS

       Examples how statistical functions are applied can be  found  in  the  r.neighbors  module
       documentation.

AUTHOR

       Glynn Clements

       Last changed: $Date: 2017-01-08 09:46:20 +0100 (Sun, 08 Jan 2017) $

SOURCE CODE

       Available at: r.resamp.stats source code (history)

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       © 2003-2018 GRASS Development Team, GRASS GIS 7.4.0 Reference Manual