Systematic-uncertainty toolsΒΆ
Heppy provides tools to explore and treat the systematic variations of histograms. This notably means combining multiple systematic variations into a single combined systematic. Some examples include:
- Combining the members of a PDF set into the PDF uncertainty
- Adding several uncorrelated uncertainties in quadrature to get a resulting net uncertainty
- Combining a set of bootstrap replicas into a final uncertainty
- Taking the envelope of perturbative QCD scale variations to get an estimate of the fixed-order calculation uncertainty
- etc.
The basic usage is:
- Create any number of
heppy.uncertainty.model
instances that specify which variations should be combined and how. - Call
heppy.uncertainty.combine_copy
, taking as arguments a histogram and a list of uncertainty models, to return a copy of the histogram where the combination models have been applied to the variations.