Add MCR-ALS analysis in Larch

[maurov]

I would like to add MCR-ALS method to Larch. Currently, one of the most used tool is the [Jaumot toolbox in Matlab. In Python, I have identified the following packages providing MRC-ALS (ordered by personal preferences):

• Spectrochempy
• PyMCR
• chemometrics

Using these packages is straightforward, but I think we should discuss how to have a common top interface (using any of those libraries as backend) that could send any matrix of spectra (not only limited to XAFS) to these workflows and get the results back.

To start, we could provide an example Jupyter notebook.

[newville]

+1 from me. There are definitely others interested in this!