Simplified likelihood from simplify tool

[sabinekraml]

Hi, this does not concern pyhf proper but, as the subject says, simplified json files produced with the simplify tool. I'm interested in knowing

• why in the simplified likelihood the background expectations are replaced with the post-fit numbers; this eliminates any information about small deviations from SM expectations, relevant for e.g. BSM fits
• how correlated uncertainties are treated in simplify: if there are both correlated and uncorrelated nuisances, how are the final region-to-region correlations determined? The mathematical description would be helpful.

Thanks! Sabine

[matthewfeickert]

@sabinekraml As these questions are about simplify I've transferred this over to simplify's repo as eschanet/simplify#19 where it can be better answered.