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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

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