GRASS GIS manual: r.stats.quantile

Note: A new GRASS GIS stable version has been released: GRASS GIS 7.8, available here.
Updated manual page: here

NAME

r.stats.quantile - Compute category quantiles using two passes.

KEYWORDS

raster, statistics, percentile, quantile

SYNOPSIS

r.stats.quantile

r.stats.quantile --help

r.stats.quantile [-rpt] base=name cover=name [quantiles=integer] [percentiles=float[,float,...]] [bins=integer] [output=name[,name,...]] [file=name] [separator=character] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-r: Create reclass map with statistics as category labels
-p: Do not create output maps; just print statistics
-t: Print statistics in table format
--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:

base=name [required]: Name of base raster map
cover=name [required]: Name of cover raster map
quantiles=integer: Number of quantiles
percentiles=float[,float,...]: List of percentiles; Default: 50
bins=integer: Number of bins to use; Default: 1000
output=name[,name,...]: Resultant raster map(s)
file=name: Name for output file (if omitted or "-" output to stdout)
separator=character: Field separator; Special characters: pipe, comma, space, tab, newline; Default: :

DESCRIPTION
NOTES
EXAMPLE
SEE ALSO
AUTHOR

DESCRIPTION

r.stats.quantile is a tool to analyse exploratory statistics of a floating-point "cover layer" according to how it intersects with objects in a "base layer". It provides quantile calculations as selected "zonal statistics".

NOTES

r.stats.quantile is intended to be a partial replacement for r.statistics, with support for floating-point cover maps. It provides quantile calculations, which are absent from r.stats.zonal.

EXAMPLE

In this example, the raster polygon map zipcodes in the North Carolina sample dataset is used to calculate quantile raster statistics using the elevation raster map:

g.region raster=zipcodes -p

# print quantiles
r.stats.quantile base=zipcodes cover=elevation quantiles=3 -p
27511:0:33.333333:134.717392
27511:1:66.666667:143.985723
27513:0:33.333333:140.669993
27513:1:66.666667:146.279449
27518:0:33.333333:115.140101
27518:1:66.666667:129.893723
[...]

# write out percentile raster maps
r.stats.quantile base=zipcodes cover=elevation percentiles=25,50,75 \
  output=zipcodes_elev_q25,zipcodes_elev_q50,zipcodes_elev_q75

AUTHOR

Glynn Clements
Markus Metz

Last changed: $Date$

SOURCE CODE

Available at: r.stats.quantile source code (history)