---
name: "r.stats.zonal"
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.zonal"
---

# r.stats.zonal(1grass)

Calculates category or object oriented statistics (accumulator-based statistics).

## NAME

**r.stats.zonal**  - Calculates category or object oriented statistics (accumulator-based statistics).

## KEYWORDS

raster, statistics, zonal statistics

## SYNOPSIS

**r.stats.zonal**\
 **r.stats.zonal --help**\
 **r.stats.zonal** \[-**cr**\] **base**=*name* **cover**=*name* **method**=*string* **output**=*name*  \[--**overwrite**\]  \[--**help**\]  \[--**verbose**\]  \[--**quiet**\]  \[--**ui**\]

### Flags:

- **-c**

  Cover values extracted from the category labels of the cover map

- **-r**

  Create reclass map with statistics as category labels

- **--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

- **method**=*string* **\[required\]**

  Method of object-based statistic\
   Options: *count, sum, min, max, range, average, avedev, variance, stddev, skewness, kurtosis, variance2, stddev2, skewness2, kurtosis2*\
   **count**: Count of values in specified objects\
   **sum**: Sum of values in specified objects\
   **min**: Minimum of values in specified objects\
   **max**: Maximum of values in specified objects\
   **range**: Range of values (max - min) in specified objects\
   **average**: Average of values in specified objects\
   **avedev**: Average deviation of values in specified objects\
   **variance**: Variance of values in specified objects\
   **stddev**: Standard deviation of values in specified objects\
   **skewness**: Skewness of values in specified objects\
   **kurtosis**: Kurtosis of values in specified objects\
   **variance2**: (2-pass) Variance of values in specified objects\
   **stddev2**: (2-pass) Standard deviation of values in specified objects\
   **skewness2**: (2-pass) Skewness of values in specified objects\
   **kurtosis2**: (2-pass) Kurtosis of values in specified objects

- **output**=*name* **\[required\]**

  Resultant raster map

## DESCRIPTION

*r.stats.zonal* is a tool to analyse exploratory statistics of a floating-point "cover layer" according to how it intersects with objects in a "base layer". A variety of standard statistical measures are possible. This type of analysis is often called *zonal statistics*. The zones are specified as the **base** raster map and the statistics are computed from cells in the **cover** raster map. Notably, the output of this module is spatial: The resulting values are recorded as cell values in the **output** raster map.

## NOTES

*r.stats.zonal* is intended to be a partial replacement for *r.statistics*, with support for floating-point cover maps at the expense of not supporting quantiles. For this, see *r.stats.quantile*.

## EXAMPLE

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

```
g.region raster=zipcodes -p
# pixel count in zipcode areas
r.stats.zonal base=zipcodes cover=elevation method=count output=zipcodes_elev_count
r.colors zipcodes_elev_count color=gyr -g
# average elevation in zipcode areas
r.stats.zonal base=zipcodes cover=elevation method=average output=zipcodes_elev_avg
r.colors zipcodes_elev_avg color=elevation -g
```

*Figure: ZIP code map on the left shows ZIP code areas,* *elevation map the respective values per pixel,* *zonal statistics map on the right shows the average elevation per zone* *(all maps: spatial subset).*

## SEE ALSO

- •

  *r.stats.quantile* for computing quantiles in zones (objects in base raster map),

- •

  *r.quantile* for computing quantiles of a whole raster map,

- •

  *r.statistics* for categorical (integer) zonal statistics,

- •

  *r.univar* for zonal statistics with textual (non-spatial) output,

- •

  *v.vect.stats* for statistics of vector points in vector areas.

## AUTHOR

Glynn Clements

## SOURCE CODE

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

Accessed: Monday Feb 24 17:50:51 2025

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