February Updates

New features

• AutoRebin class. Modifies the binning of the shapes in a CH instance using pre-defined algorithms and thresholds on the minimum bin content and uncertainty. For usage and available algorithms see the documentation here. Note that this has only been tested in the context of the MSSM analysis and will likely evolve in the future. Can be used in both the C++ and python interfaces.
• The reading and writing of counting experiment datacards is now supported, and a new overloaded WriteDatacard method has been added which requires only the name of the text file and not a ROOT file. (#23)
• The reading, writing and creation of rateParam datacard directives is now supported. These make it simple to introduce new floating parameters for scaling the backgrounds, and in particular for tying together the normalisations of processes in different categories. These terms can also be written as functions of other parameters. A new example script has been added to illustrate the usage in CH. See the combine twiki for more information on these rateParam terms. (#24)
• Nuisance parameter groups are now supported in CombineHarvester. These are special lines in the datacard which group sets of parameters under a common label, which can then be used to freeze/unfreeze the whole group in combine. See further details on the combine twiki. Group information in the datacards is parsed and written automatically, and the methods SetGroup and RemoveGroup have been added for creating new groups or removing parameters from groups using lists of regular expressions. (#25).
• Several updates to the combineTool.py script, mostly to support operating on multiple datacards/workspaces in one go. A new documentation page has been added to explain these features in more detail (link).
  • New T2W method that can do the combineCards.py and text2workspace.py steps and infer the mass value from the name of the enclosing directory.
  • Support for multiple datacards in the EnhancedCombine mode combineTool.py, again with the -m option set automatically.
  • CollectLimits can create multiple output files based on the directory structure of the combine output files
• Large rewrite of plotLimits.py to support traditional green/yellow band expected limits as well as individual limit comparisons. Basic usage is covered in the new documentation page linked in the previous item.
• Added an example script for the usage of the ParseCombineWorkspace function, CombineTools/scripts/parseCombineWorkspaceExample.py (2222e09)

Bug fixes

• Histograms written into TFiles by CombineHarvester and PostFitShapes would often have a different TObject name than the key used to write the object into the directory. The function doing the writing now ensures the key and object name are the same. (c56242b)