Docs for ‘QGIS testing’. Visit http://docs.qgis.org/2.18 for QGIS 2.18 docs and translations.

R algorithm provider

R also called GNU S, is a strongly functional language and environment to statistically explore data sets, make many graphical displays of data from custom data sets

Note

Please remember that Processing contains only R scripts, so you need to install R by yourself and configure Processing properly.