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UHHAnalysis / ZprimeAnalysis

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What is this code doing? #13

Closed xerxes1986 closed 10 years ago

xerxes1986 commented 10 years ago

On line 200ish of analysis.py:

 for p in model.distribution.get_parameters():
      d = model.distribution.get_distribution(p)
      if d['typ'] == 'gauss' and d['mean'] == 0.0 and d['width'] == 1.0:
          model.distribution.set_distribution_parameters(p, range = [-5.0, 5.0])

What is this code doing? I cannot find ANYTHING about this in the theta documentation and I am unaware why it is in the file at all.

peiffer commented 10 years ago

This lines restrict all gaussian nuisance parameters to a range between -5sigma and +5sigma. The default range would be -infinity to +infinity. I do not remember why we are using this restriction, but it shouldn't make any sizeable difference. Perhaps their were some numerical instabilities when running the fit without any restrictions to the nuisance parameters.

xerxes1986 commented 10 years ago

Ok, thanks for the clarification. Seeing as how the nuisance parameters I showed today are all within +-2 sigma, so this should really affect anything.