---
name: r.li.shannon
description: Calculates Shannon's diversity index on a raster map
keywords: [ raster, landscape structure analysis, diversity index ]
---

# r.li.shannon

Calculates Shannon's diversity index on a raster map

=== "Command line"

    **r.li.shannon**
    **input**=*name*
    **config**=*name*
    **output**=*name*
    [**--overwrite**]
    [**--verbose**]
    [**--quiet**]
    [**--qq**]
    [**--ui**]

    Example:

    ```sh
    r.li.shannon input=name config=name output=name
    ```

=== "Python (grass.tools)"

    *grass.tools.Tools.r_li_shannon*(**input**,
        **config**,
        **output**,
        **overwrite**=*None*,
        **verbose**=*None*,
        **quiet**=*None*,
        **superquiet**=*None*)

    Example:

    ```python
    tools = Tools()
    tools.r_li_shannon(input="name", config="name", output="name")
    ```

    This grass.tools API is experimental in version 8.5 and expected to be stable in version 8.6.

=== "Python (grass.script)"

    *grass.script.run_command*("***r.li.shannon***",
        **input**,
        **config**,
        **output**,
        **overwrite**=*None*,
        **verbose**=*None*,
        **quiet**=*None*,
        **superquiet**=*None*)

    Example:

    ```python
    gs.run_command("r.li.shannon", input="name", config="name", output="name")
    ```

## Parameters

=== "Command line"

    **input**=*name* **[required]**  
    &nbsp;&nbsp;&nbsp;&nbsp;Name of input raster map  
    **config**=*name* **[required]**  
    &nbsp;&nbsp;&nbsp;&nbsp;Configuration file  
    **output**=*name* **[required]**  
    &nbsp;&nbsp;&nbsp;&nbsp;Name for output raster map  
    **--overwrite**  
    &nbsp;&nbsp;&nbsp;&nbsp;Allow output files to overwrite existing files  
    **--help**  
    &nbsp;&nbsp;&nbsp;&nbsp;Print usage summary  
    **--verbose**  
    &nbsp;&nbsp;&nbsp;&nbsp;Verbose module output  
    **--quiet**  
    &nbsp;&nbsp;&nbsp;&nbsp;Quiet module output  
    **--qq**  
    &nbsp;&nbsp;&nbsp;&nbsp;Very quiet module output  
    **--ui**  
    &nbsp;&nbsp;&nbsp;&nbsp;Force launching GUI dialog

=== "Python (grass.tools)"

    **input** : str | np.ndarray, *required*  
    &nbsp;&nbsp;&nbsp;&nbsp;Name of input raster map  
    &nbsp;&nbsp;&nbsp;&nbsp;Used as: input, raster, *name*  
    **config** : str | io.StringIO, *required*  
    &nbsp;&nbsp;&nbsp;&nbsp;Configuration file  
    &nbsp;&nbsp;&nbsp;&nbsp;Used as: input, file, *name*  
    **output** : str | type(np.ndarray) | type(np.array) | type(gs.array.array), *required*  
    &nbsp;&nbsp;&nbsp;&nbsp;Name for output raster map  
    &nbsp;&nbsp;&nbsp;&nbsp;Used as: output, raster, *name*  
    **overwrite** : bool, *optional*  
    &nbsp;&nbsp;&nbsp;&nbsp;Allow output files to overwrite existing files  
    &nbsp;&nbsp;&nbsp;&nbsp;Default: *None*  
    **verbose** : bool, *optional*  
    &nbsp;&nbsp;&nbsp;&nbsp;Verbose module output  
    &nbsp;&nbsp;&nbsp;&nbsp;Default: *None*  
    **quiet** : bool, *optional*  
    &nbsp;&nbsp;&nbsp;&nbsp;Quiet module output  
    &nbsp;&nbsp;&nbsp;&nbsp;Default: *None*  
    **superquiet** : bool, *optional*  
    &nbsp;&nbsp;&nbsp;&nbsp;Very quiet module output  
    &nbsp;&nbsp;&nbsp;&nbsp;Default: *None*  

    Returns:

    **result** : grass.tools.support.ToolResult | np.ndarray | tuple[np.ndarray] | None  
    If the tool produces text as standard output, a *ToolResult* object will be returned. Otherwise, `None` will be returned. If an array type (e.g., *np.ndarray*) is used for one of the raster outputs, the result will be an array and will have the shape corresponding to the computational region. If an array type is used for more than one raster output, the result will be a tuple of arrays.

    Raises:

    *grass.tools.ToolError*: When the tool ended with an error.

=== "Python (grass.script)"

    **input** : str, *required*  
    &nbsp;&nbsp;&nbsp;&nbsp;Name of input raster map  
    &nbsp;&nbsp;&nbsp;&nbsp;Used as: input, raster, *name*  
    **config** : str, *required*  
    &nbsp;&nbsp;&nbsp;&nbsp;Configuration file  
    &nbsp;&nbsp;&nbsp;&nbsp;Used as: input, file, *name*  
    **output** : str, *required*  
    &nbsp;&nbsp;&nbsp;&nbsp;Name for output raster map  
    &nbsp;&nbsp;&nbsp;&nbsp;Used as: output, raster, *name*  
    **overwrite** : bool, *optional*  
    &nbsp;&nbsp;&nbsp;&nbsp;Allow output files to overwrite existing files  
    &nbsp;&nbsp;&nbsp;&nbsp;Default: *None*  
    **verbose** : bool, *optional*  
    &nbsp;&nbsp;&nbsp;&nbsp;Verbose module output  
    &nbsp;&nbsp;&nbsp;&nbsp;Default: *None*  
    **quiet** : bool, *optional*  
    &nbsp;&nbsp;&nbsp;&nbsp;Quiet module output  
    &nbsp;&nbsp;&nbsp;&nbsp;Default: *None*  
    **superquiet** : bool, *optional*  
    &nbsp;&nbsp;&nbsp;&nbsp;Very quiet module output  
    &nbsp;&nbsp;&nbsp;&nbsp;Default: *None*

## DESCRIPTION

*r.li.shannon* calculates the "Shannon's diversity index" as:  
![r.li.shannon formula](r_li_shannon_formula.png)  
with:

- *i*: patch type
- *m*: number of different patch types
- *p_i*: proportional abundance of patch type *i*

## NOTES

Do not use absolute path names for the **config** and **output**
file/map parameters. If the "moving window" method was selected in
**g.gui.rlisetup**, then the output will be a raster map, otherwise an
ASCII file will be generated in the folder
`C:\Users\userxy\AppData\Roaming\GRASS8\r.li\output\` (MS-Windows) or
`$HOME/.grass8/r.li/output/` (GNU/Linux).

If the input raster map contains only NULL values then *r.li.shannon*
returns NULL.

## EXAMPLES

To calculate Shannon's diversity index on map *my_map*, using *my_conf*
configuration file (previously defined with *g.gui.rlisetup*) and saving
results in *my_out*, run:

```sh
r.li.shannon input=my_map conf=my_conf output=my_out
```

Forest map (Spearfish sample dataset) example:

```sh
g.region raster=landcover.30m -p
r.mapcalc "forests = if(landcover.30m >= 41 && landcover.30m <= 43,1,null())"
r.li.shannon input=forests conf=movwindow7 out=forests_shannon_mov7
r.univar forests_shannon_mov7
```

Forest map (North Carolina sample dataset) example:

```sh
g.region raster=landclass96 -p
r.mapcalc "forests = if(landclass96 == 5, 1, null() )"
r.li.shannon input=forests conf=movwindow7 out=forests_shannon_mov7

# verify
r.univar forests_shannon_mov7
r.to.vect input=forests output=forests type=area
d.mon wx0
d.rast forests_shannon_mov7
d.vect forests type=boundary
```

## SEE ALSO

*[r.li](r.li.md) (package overview),
[g.gui.rlisetup](g.gui.rlisetup.md)*

## REFERENCES

McGarigal, K., and B. J. Marks. 1995. FRAGSTATS: spatial pattern
analysis program for quantifying landscape structure. USDA For. Serv.
Gen. Tech. Rep. PNW-351. ([PDF](https://doi.org/10.2737/PNW-GTR-351))

## AUTHORS

Serena Pallecchi, student of Computer Science University of Pisa
(Italy).  
Commission from Faunalia Pontedera (PI), Italy (<www.faunalia.it>)

## SOURCE CODE

Available at: [r.li.shannon source code](https://github.com/OSGeo/grass/tree/main/raster/r.li/r.li.shannon)
([history](https://github.com/OSGeo/grass/commits/main/raster/r.li/r.li.shannon))  
Accessed: Saturday May 09 12:58:18 2026
