r.stats.quantile(1grass)

Usage

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]

Keywords

raster, statistics, zonal statistics, percentile, quantile

Overview

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.

Quantiles are calculated following algorithm 7 from Hyndman and Fan (1996), which is also the default in R and numpy.

Examples

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

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

Source code

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

Accessed: Monday Feb 24 17:50:52 2025

Releases

5 releases since Debian 9 (Stretch); the text changed 4 times.

9
10
11
12
13