Using the "low level" Sherpa API to fit PHA spectra

[DougBurke]

Brian, I should have mentioned my set of "unofficial" notebooks I occasionally update - you can find them at https://github.com/DougBurke/sherpa-standalone-notebooks and I think the following may be helpful (or at least I hope it is) https://github.com/DougBurke/sherpa-standalone-notebooks/blob/master/Fitting%20a%20PHA%20dataset%20using%20the%20object%20API.ipynb

[bcalden]

This is tremendous! Thank you for putting this together and sharing it with me. Apologies for the delayed response :)

[DougBurke]

I will say that the documentation at https://sherpa.readthedocs.io/ has improved since I wrote this (but there's still more that could be done).