---
name: "r.stats.quantile"
section: "1grass"
platform: "linux"
package: "grass-doc"
version: "8.4.1-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/r.stats.quantile"
---

# r.stats.quantile(1grass)

Compute category quantiles using two passes.

## NAME

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

## KEYWORDS

raster, statistics, zonal 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

*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.

## 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
```

## 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.quantile,* *r.stats.zonal,* *r.statistics*

## AUTHORS

Glynn Clements\
 Markus Metz

## SOURCE CODE

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

Accessed: Monday Feb 24 17:50:52 2025

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