How to add my own GRASS algorithms to Processing?

Question

I need to use algorithm r.bioclimatic from GRASS in QGIS but I see that this algorithm don't exist in Processing Toolbox. A search a way of add this algorithm to Processing and in GRASS and Sextante page if find this way:

HOWTO adding own GRASS algorithms to Sextante (simply by adding a new description file)

I create a description file according to the rules but now I don't know how to run and if this will run in GRASS.

The first parameters of r.bioclimatic (tmin, tmax....) are columns of tables? I don't know which type of input I have.

Answer 1

r.bioclim (I suppose, because r.bioclimatic don't exist), is an GRASS GIS 7 addon

If you want to create or modify an algorithm, read the file ../processing/algs/grass7/grass7.txt that begins with "A short guide for creating and editing GRASS GIS 7 algorithms"

But, how do these commands work ?

• to use the GRASS7 commands in processing,you need to first specify the GRASS GIS installation (in Processing/options) and processing will look for scripts that are in the folders bin and scripts of your GRASS installation (GISBASE environment variable) in the script ../processing/algs/grass7/Grass7AlgorithmProvider.py
• the script is executed with the Python module subprocess in the ../processing/algs/grass7/Grass7Utils.py script

The big problem is that the addons are not installed in these folders (GRASS_ADDON_PATH environment variable) therefore you can simply use them with processing

Conclusion ? QGIS is not GRASS GIS and if you want to use a "specialized" algorithm (addon), use GRASS GIS

Answer 2

To complete the Gene's answer consider that you can install addons at system level when installing it with g.extension using the "-s" option. In this way the algorithm is found out by processing.

So you can keep using GRASS inside QGIS!