rooFit Scripts

RooFit_ReadHisto_Fit.py

# (RooFit) Read Histogram from root file and fit using RooFit


import ROOT as r

from ROOT import RooErfExpPdf

fin = r.TFile.Open("root://cmseos.fnal.gov//store/user/rasharma/SecondStep/WWTree_2018_01_07_12h02/HaddedFiles/Hadds_for_BkgEstimation/WWTree_WJets.root")

treeIn = fin.Get("otree")

c1 = r.TCanvas("c1","c1",800,600)

h1 = r.TH1F("h1","",22,40,150)

treeIn.Draw("PuppiAK8_jet_mass_so>>h1",cutString)

x		= r.RooRealVar("x","AK8 invariant mass",40,150);
offset = r.RooRealVar("offset","offset",60.,30.,120);
width  = r.RooRealVar("width","width",30.,10, 60.);

model_pdf = r.RooGaussian("model_pdf","gaussian function",x, offset, width)

print "Entries from MC = ",h1.GetEntries(),h1.Integral()

dh =  r.RooDataHist("dh","plotOn test data with x",r.RooArgList(x),h1)

model_pdf.fitTo(dh)

rfresult =  model_pdf.createIntegral(r.RooArgSet(x))

print rfresult.getVal() 


frame = rrv_x.frame() 
dh.plotOn(frame)
dh.statOn(frame);  #this will display hist stat on canvas
model_pdf.plotOn(frame)
model_pdf.paramOn(frame);
frame.Draw()