ROOT Version: 6.06/01
Platform: Ubuntu 16.04
Hello, root experts.
I have a question for usage of Sumw2 function in my situation.
At the moment, I am filling my histogram in given way
sample ='ZH_HToSSTobbbb_ZToLL_MH-125_MS-15_ctauS-10 & 5' h16 = TH1F("Decaydist",'%s Decaydist' % sample,100, 0, 100) h16w = TH1F("Decaydistw",'%s Decaydistw' % sample,100, 0, 100) h16w.Sumw2() h16s = TH1F("ctauEventWeight",'%s ctauEventWeight' % sample,80, 0, 4) DY16dir=glob.glob('path/0000/*') for i in range (7): filename = DY16dir[i] _file0 = TFile.Open(filename,'read') mytree16 = _file0.Get("lldjNtuple/EventTree") for entry in mytree16: ctau = mytree16.ctauEventWeight h16s.Fill(ctau,1) #print(ctau) Decaydist=mytree16.AODnVtx h16.Fill(Decaydist,1) h16w.Fill(Decaydist,ctau)
As you can see, h16w hist is weighted with ctau with predefined condition of h16w.Sumw2()
At the end, the plot looks like
Technically, the integral of the red(h16) and the blue(h16w) should be equal to each other, but differ a little bit in my case.
I want to prove that the discrepancy in integral is OK because the difference is within the error range of the integral of the Weighted (blue, h16w) histogram".
How can I get the error range in the integral of the blue histogram, using the Sumw2?
Do you have any good idea?