The nice Get R scripts from on-line scripts collection mechanism of QGIS 2 was discontinued when R support in QGIS was moved to the Processing R Provider plugin.
The reason for this was that the Resource sharing mechanism, provided by the QGIS Resource Sharing plugin should be used for all kinds of sharable resources, including R scripts.
But R script support was not included in the Resource Sharing plugin from the start, meaning that it became rather inconvenient to add example R scripts to the Processing toolbox.
With version 0.9.0 of the Resource Sharing plugin, made available on plugins.qgis.org today, this has changed (https://plugins.qgis.org/plugins/qgis_resource_sharing/). To add the QGIS online R scripts collection you can now:
- Install the plugin, using the plugin manager.
- Start it (from Plugins-> Resource Sharing-> Resource Sharing).
- Go to Settings and click on the Reload Repositories button.
- Go to All and select QGIS R script collection.
- Click on the Install button.
If you have R and the Processing R Provider plugin installed and configured properly, scripts from the original QGIS 2 R script online collection should be available under R in the processing toolbox now.
https://gis.stackexchange.com/a/348772/22646 contains a screenshot of the Processing toolbox with these scripts installed.
Since QGIS R support now relies on the sf package for input and output, only the QGIS 2 R scripts that do not rely on spatial input / output will work "out of the box". It is reasonably easy to also make the spatial ones work, and I hope to include more scripts from the QGIS 2 collection soon.
I have done some porting already, and you can get some working examples through the Resource Sharing plugin by adding the repository https://github.com/havatv/QGIS-Resources.git, reloading repositories and installing QGIS R script collection.
The R scripts used in QGIS 2 also work with the Processing R Provider plugin in QGIS 3 (since 3.4).
Some of the scripts have now been
If you would like to use QGIS R scripts from the collection and don't have it in a .qgis2 folder, you can find the collection on
https://github.com/qgis/QGIS-Processing/tree/master/rscripts (archived repository)
Just download the rsx file and place it into your rscripts folder
(~/.local/share/QGIS/QGIS3/profiles/default/processing/rscripts on Ubuntu). It will then become available in the Processing Toolbox.