# fasterRaster addons

#### Adam B. Smith

#### 2025-02-25

GRASS GIS comes with a default set of modules (functions), but users can download and install “addon” modules to extend its capabilities. Some of the functions in fasterRaster rely on these addon modules. To make these functions work, you must find the folder in which addons are stored and install the desired module.

1. Installing modules: The easiest (only?) way to do this is to start GRASS (not in R through fasterRaster, but actually start GRASS), then use the `Settings` menu’s `Addon extensions` option, then select `Install extensions from addons [g.extension]`. GRASS should display a list of addons you can install.

2. Once you have the desired extension(s) installed, you can use fasterRaster functions that call them. To do this, you need to specify the `addons` folder before starting GRASS (i.e., before the first time you use the `fast()` function to load a raster or vector). Use `faster()` to tell fasterRaster where this folder is. The folder will vary by operating system. On a Windows machine, it will be something like:

    C:/Users/your_windows_user_name/AppData/Roaming/GRASS8/addons

You can set the addons folder using `faster(addonsDir = "C:/Users/your_windows_user_name/AppData/Roaming/GRASS8/addons")`.

## Validating addons

You can test to see if the `addons` folder is correct using `addons()`. You can also see if a particular addon module was installed correctly using the same function using, for example, `addons("v.centerpoint")`.

## fasterRaster functions that need addons

These functions must have the specified addon to work.

Function | addon
--- | ---
`centroids()` | `v.centerpoint`

~ FINIS ~