r.quantile
Compute quantiles using two passes.
r.quantile [-r] input=name [quantiles=integer] [percentiles=float [,float,...]] [bins=integer] [file=name] [--overwrite] [--verbose] [--quiet] [--qq] [--ui]
Example:
r.quantile input=name
grass.script.run_command("r.quantile", input, quantiles=4, percentiles=None, bins=1000000, file=None, flags=None, overwrite=False, verbose=False, quiet=False, superquiet=False)
Example:
gs.run_command("r.quantile", input="name")
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
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
--qq
Very quiet module output
--ui
Force launching GUI dialog
input : str, required
Name of input raster map
Used as: input, raster, name
quantiles : int, optional
Number of quantiles
Default: 4
percentiles : float | list[float] | str, optional
List of percentiles
bins : int, optional
Number of bins to use
Default: 1000000
file : str, optional
Name for output file (if omitted or "-" output to stdout)
Used as: output, file, name
flags : str, optional
Allowed values: r
r
Generate recode rules based on quantile-defined intervals
overwrite: bool, optional
Allow output files to overwrite existing files
Default: False
verbose: bool, optional
Verbose module output
Default: False
quiet: bool, optional
Quiet module output
Default: False
superquiet: bool, optional
Very quiet module output
Default: False
DESCRIPTION
r.quantile computes quantiles in a manner suitable for use with large amounts of data. It is using two passes.
NOTES
Quantiles are calculated following algorithm 7 from Hyndman and Fan (1996), which is also the default in R and numpy.
EXAMPLE
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=-
REFERENCES
- Hyndman and Fan (1996) Sample Quantiles in Statistical Packages, American Statistician. American Statistical Association. 50 (4): 361-365. DOI: 10.2307/2684934
- Engineering Statistics Handbook: Percentile, NIST
SEE ALSO
r.mode, r.quant, r.recode, r.series, r.stats, r.stats.quantile, r.stats.zonal, r.statistics, r.univar, v.rast.stats
AUTHORS
Glynn Clements
Markus Metz
SOURCE CODE
Available at: r.quantile source code
(history)
Latest change: Friday Feb 07 19:16:09 2025 in commit a82a39f