NAME
r.clump - Recategorizes data in a raster map layer by grouping cells
that form physically discrete areas into unique categories.
(GRASS Raster Program)
SYNOPSIS
r.clump
r.clump help
r.clump [-q] input=name output=name [TITLE="string"]
DESCRIPTION
r.clump finds all areas of contiguous cell category values in the input
raster map layer name. It assigns a unique category value to each
such area ("clump") in the resulting output raster map layer name.
If the user does not provide input and output map layer names
on the command line, the program will prompt the user for these names,
using the standard
parser
interface (see manual entry for parser).
Category distinctions in the input raster map layer 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.)
Flag:
- -q
- Run quietly, without printing messages on program
progress to standard output.
Parameters:
- input=name
- Name of an existing raster map layer being used for input.
- output=name
- Name of new raster map layer to contain program output.
- TITLE="string"
- Optional TITLE for output raster map layer, in quotes.
If the user fails to assign a TITLE for the output map layer,
none will be assigned it.
ALGORITHM
r.clump moves a 2x2 matrix over the input raster map layer.
The lower right-hand corner of the matrix is grouped with the cells above it,
or to the left of it.
(Diagonal cells are not considered.)
NOTES
r.clump works properly with raster map layers that
contain 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.
A random color table and other support files are
generated for the output raster map layer.
SEE ALSO
r.average
r.buffer
r.combine
r.grow
r.infer
r.mapcalc
r.mfilter
r.neighbors
r.poly
r.reclass
r.support
r.weight
parser
AUTHOR
Michael Shapiro, U.S. Army Construction Engineering
Research Laboratory