def mergeHistsFromMapping(hists, mapping, fillcolors=None):
"""
merge histograms from mappping.
e.g.
- hists {'a_1': Hist(), 'a_2': Hist(), ... , 'b_1': Hist(), 'b_2': Hist()}
- mapping {'a': ['a_1', 'a_2',], 'b': ['b_1', 'b_2']}
- fillcolors [optional] {'a': 'green', 'b': 'red'}
- returns OrderedDict('a': Hist(), 'b': Hist()) sorted by Integral()
"""
from collections import OrderedDict
CatHists = {}
for cat, ds in mapping.items():
output = None
for d in ds:
if output is None:
output = hists[d].Clone()
ROOT.SetOwnership(output, False)
else:
output.Add(hists[d])
if fillcolors:
output.fillcolor = fillcolors[cat]
output.SetTitle(cat)
CatHists[cat] = output
return OrderedDict(sorted(CatHists.items(), key=lambda x: x[1].Integral()))
def ErrorBandFromHistStack(hstack, **kwargs):
"""
possion error band (TGraphAsymmError) from sum of `hstack`
kwargs are forwarded for TGraphAsymmError property setting
"""
_sumStack = sumHistStack(hstack)
stackError = asrootpy(_sumStack) #.poisson_errors()
ROOT.SetOwnership(stackError, False)
kwDefaults = {
'fillstyle': 3244,
'fillcolor': 'gray',
'drawstyle': 'e2',
'markersize': 0,
'legendstyle': 'F',
'title': 'stat. unc',
}
kwDefaults.update(kwargs)
for k, v in kwDefaults.items():
setattr(stackError, k, v)
return stackError
