core.PileUpAnalyzer.PileUpAnalyzer Class Reference

Inheritance diagram for core.PileUpAnalyzer.PileUpAnalyzer:

Public Member Functions
def	__init__
def	beginLoop
def	declareHandles
def	process
def	write

Public Attributes
	allVertices
	datafile
	datahist
	doHists
	enable
	if component is embed return (has no trigger obj) More...
	mcfile
	mchist
	rawmcpileup

Static Public Attributes
	class_object = PileUpAnalyzer,
	makeHists = False
	true = True,

Detailed Description

Computes pile-up weights for MC from the pile up histograms for MC and data.
These histograms should be set on the components as
puFileData, puFileMC attributes, as is done here:

http://cmssw.cvs.cern.ch/cgi-bin/cmssw.cgi/UserCode/CMG/CMGTools/H2TauTau/Colin/test_tauMu_2012_cfg.py?view=markup

THESE HISTOGRAMS MUST BE CONSISTENT, SEE
https://twiki.cern.ch/twiki/bin/view/CMS/CMGToolsPileUpReweighting#Generating_pile_up_distributions

If the component is not MC, or if the puFileData and puFileMC are not
set for the component, the reweighting is not done. 

The analyzer sets event.vertexWeight.
This weight is multiplied to the global event weight, event.eventWeight.
When using this analyzer, make sure that the VertexAnalyzer is disabled,
as you would be reweighting the MC PU distribution twice!

Additionally, this analyzer writes in the output an histogram containing the unweighting MC
pile-up distribution, to be used in input of the weighting for a later pass. 

Example of use: 

puAna = cfg.Analyzer(
  "PileUpAnalyzer",
  # build unweighted pu distribution using number of pile up interactions if False
  # otherwise, use fill the distribution using number of true interactions
  true = True
  )

Definition at line 11 of file PileUpAnalyzer.py.

Constructor & Destructor Documentation

def core.PileUpAnalyzer.PileUpAnalyzer.__init__	(		self,
			cfg_ana,
			cfg_comp,
			looperName
	)

Definition at line 42 of file PileUpAnalyzer.py.

    def __init__(self, cfg_ana, cfg_comp, looperName):
        super(PileUpAnalyzer, self).__init__(cfg_ana, cfg_comp, looperName)

        self.doHists=True

        if (hasattr(self.cfg_ana,'makeHists')) and (not self.cfg_ana.makeHists):
            self.doHists=False

        self.allVertices = self.cfg_ana.allVertices if (hasattr(self.cfg_ana,'allVertices')) else "_AUTO_"

        if self.cfg_comp.isMC and self.doHists:
            self.rawmcpileup = VertexHistograms('/'.join([self.dirName,
                                                          'rawMCPU.root']))
        self.enable = True
        ## if component is embed return (has no trigger obj)
        if self.cfg_comp.isEmbed :
          self.cfg_comp.puFileMC   = None
          self.cfg_comp.puFileData = None
          
        if self.cfg_comp.isMC or self.cfg_comp.isEmbed:
            if not hasattr(self.cfg_comp,"puFileMC") or (self.cfg_comp.puFileMC is None and self.cfg_comp.puFileData is None):
                self.enable = False
            else:
                assert( os.path.isfile(os.path.expandvars(self.cfg_comp.puFileMC)) )
                assert( os.path.isfile(os.path.expandvars(self.cfg_comp.puFileData)) )

                self.mcfile = TFile( self.cfg_comp.puFileMC )
                self.mchist = self.mcfile.Get('pileup')
                self.mchist.Scale( 1 / self.mchist.Integral() )

                self.datafile = TFile( self.cfg_comp.puFileData )
                self.datahist = self.datafile.Get('pileup')
                self.datahist.Scale( 1 / self.datahist.Integral() )
                # import pdb; pdb.set_trace()
                if self.mchist.GetNbinsX() != self.datahist.GetNbinsX():
                    raise ValueError('data and mc histograms must have the same number of bins')
                if self.mchist.GetXaxis().GetXmin() != self.datahist.GetXaxis().GetXmin():
                    raise ValueError('data and mc histograms must have the same xmin')
                if self.mchist.GetXaxis().GetXmax() != self.datahist.GetXaxis().GetXmax():
                    raise ValueError('data and mc histograms must have the same xmax')