 
NAME
r.quantile  - Compute quantiles using two passes.
KEYWORDS
raster, 
algebra, 
statistics, 
percentile, 
quantile
SYNOPSIS
r.quantile
r.quantile --help
r.quantile [-r] input=name  [quantiles=integer]   [percentiles=float[,float,...]]   [bins=integer]   [file=name]   [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui] 
Flags:
- -r
- Generate recode rules based on quantile-defined intervals
- --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
- quantiles=integer
- Number of quantiles
- Default: 4
- percentiles=float[,float,...]
- List of percentiles
- bins=integer
- Number of bins to use
- Default: 1000000
- file=name
- Name for output file (if omitted or "-" output to stdout)
 
r.quantile computes quantiles in a manner suitable
for use with large amounts of data. It is using two passes.
Quantiles are calculated following algorithm 7 from Hyndman and Fan (1996),
which is also the default in R and numpy.
Calculation of elevation quantiles (printed to standard-out):
g.region raster=elevation -p
r.quantile input=elevation percentiles=0.1,1,10,25,50,75,90,99,99.9
The output of 
r.quantile can be used for quantile classification:
g.region raster=elevation -p
r.quantile elevation quantiles=5 -r --quiet | r.recode elevation \
           out=elev_quant5 rules=-
Glynn Clements
Markus Metz
SOURCE CODE
  Available at:
  r.quantile source code
  (history)
  Latest change: Thursday Jan 26 14:10:26 2023 in commit: cdd84c130cea04b204479e2efdc75c742efc4843
Main index |
Raster index |
Topics index |
Keywords index |
Graphical index |
Full index
© 2003-2025
GRASS Development Team,
GRASS GIS 8.4.1 Reference Manual