NAME

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

KEYWORDS

       raster, resample, univariate statistics, aggregation

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

SOURCE CODE

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

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual