NAME
r.random.weight - Generates a binary raster layer with a random selection of raster cells depending on the weight of each cell in the input weight layer.
KEYWORDS
raster,
sampling,
random
SYNOPSIS
r.random.weight
r.random.weight --help
r.random.weight [-sn] weights=raster output=raster [start=float] [end=float] [subsample=string] [seed=integer] [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags:
- -s
- Generate random seed (result is non-deterministic)
- -n
- set non-selected values to 0 (default to NULL)
- --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:
- weights=raster [required]
- layer with weight
- output=raster [required]
- output layer
- start=float
- minimum weight
- end=float
- maximum weight
- subsample=string
- subsample
- seed=integer
- set seed for random number generation
r.rand.weight generates a binary raster layer with a random
selection of raster cells which are assigned 1. The other cells are
assigned NULL (or optionally 0). The change for a raster cell to get
assigned a 1 (to get selected) depends on the weight (value) of that
cell in the input weight layer.
By default the script is run setting a random seed every time. To
ensure that your results are reproducible you can set the seed value
under the 'Sample options' tab. See the 'Random number generator
initialization' in the r.mapcalc helpfile for more details.
You can play with the probability for a cell to be selected by
changing the minimum and/or maximum weights. The script will give a
warning if the user defined minimum > minimum raster value or if the
user defined maximum is smaller then the maximum raster value. The
script will still run as the user may have set this values
intentionally.
You can also set the total number of sample points to be selected
using the under the 'Sample options' tab. This can be done using an
absolute number or as percentage (see the help file of the r.random
function for more details).
See
here for examples
r.random,
r.random.cells
Paulo van Breugel, paulo at ecodiv.org
SOURCE CODE
Available at:
r.random.weight source code
(history)
Latest change: Sunday Jun 04 10:56:41 2023 in commit: 7155c1c6f5cf60c88602a1c84411116bc179bd99
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GRASS Development Team,
GRASS GIS 8.4.1dev Reference Manual