xenial (1) r.clump.1grass.gz

NAME

       r.clump   - Recategorizes data in a raster map by grouping cells that form physically discrete areas into
       unique categories.

KEYWORDS

       raster, statistics, reclass, clumps

SYNOPSIS

       r.clump
       r.clump --help
       r.clump  [-dg]  input=name   [output=name]    [title=string]     [--overwrite]    [--help]    [--verbose]
       [--quiet]  [--ui]

   Flags:
       -d
           Clump also diagonal cells
           Clumps are also traced along diagonal neighboring cells

       -g
           Print only the number of clumps in shell script style

       --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
           Name for output raster map

       title=string
           Title for output raster map

DESCRIPTION

       r.clump  finds  all  areas of contiguous cell category values in the input raster map. NULL values in the
       input are ignored. It assigns a unique category value to each such area ("clump") in the resulting output
       raster map.

       Category distinctions in the input raster map are preserved.  This means that if distinct category values
       are adjacent, they will NOT be clumped  together.  The  user  can  run  r.reclass  prior  to  r.clump  to
       recategorize cells and reassign cell category values.

NOTES

       By  default,  the  resulting  clumps are connected only by their four direct neighbors (left, right, top,
       bottom). The -d flag activates also diagonal clump tracing.

       r.clump works properly with raster map that contains only "fat" areas (more than a single cell in width).
       Linear  elements  (lines that are a single cell wide) may or may not be clumped together depending on the
       direction of the line - horizontal and vertical lines of cells  are  considered  to  be  contiguous,  but
       diagonal lines of cells are not considered to be contiguous and are broken up into separate clumps unless
       the -d flag is used.

       A random color table and other support files are generated for the output raster map.

EXAMPLES

       Perform clumping on "lakes" map (North Carolina sample dataset) and  report  area  sizes  for  each  lake
       individually rather by waterbody type:
       g.region raster=lakes -p
       # report sizes by waterbody type
       r.report lakes units=h
       # clump per raster polygon
       r.clump lakes out=lakes_individual
       # report sizes by individual waterbody
       r.report lakes_individual units=h

SEE ALSO

         r.average,  r.buffer,  r.distance,  r.grow  r.mapcalc,  r.mfilter,  r.neighbors,  r.to.vect, r.reclass,
       r.statistics, r.support

AUTHOR

       Michael Shapiro, U.S. Army Construction Engineering Research Laboratory
       Markus Metz (diagonal clump tracing)

       Last changed: $Date: 2014-12-19 22:55:37 +0100 (Fri, 19 Dec 2014) $

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