No of events in the bins

Newbie
1

Hello rooters,
I need to find out number of events in each bin.(see attached plot)
For that I wrote a little code.I got 0 events . I am not sure why GetBinContent is not working.

void NoOfEvents(){
    int i_Q2_bins=4;
    int i_xBj=7;
    
    char histName[64];
   int events;
    
    TH1F *h_pion_invariant_mass[i_Q2_bins][i_xBj];
    
    TFile *hFile1=TFile::Open("MC_generated.root");
    hFile1->ls();
    
    for(int iQ2=0; iQ2 < i_Q2_bins; iQ2++){
        for(int ixB=0; ixB <i_xBj; ixB++ ){
        
            sprintf(histName,"h_pioninvariantmass_Q2%03d_xB%03d", iQ2,ixB);
            h_pion_invariant_mass[iQ2][ixB]=(TH1F *) hFile1->Get(histName);
            events = h_pion_invariant_mass[iQ2][ixB]->GetBinContent(iQ2,ixB);
            printf("events_Q2%03d_xB%03d = %d \n",iQ2,ixB,events);
        }
    }
    
    
    
}



events_Q2000_xB000 = 0 
events_Q2000_xB001 = 0 
events_Q2000_xB002 = 0 
events_Q2000_xB003 = 0 
events_Q2000_xB004 = 0 
events_Q2000_xB005 = 0 
events_Q2000_xB006 = 0 
events_Q2001_xB000 = 0 
events_Q2001_xB001 = 0 
events_Q2001_xB002 = 0 
events_Q2001_xB003 = 0 
events_Q2001_xB004 = 0 
events_Q2001_xB005 = 0 
events_Q2001_xB006 = 0 
events_Q2002_xB000 = 0 
events_Q2002_xB001 = 0 
events_Q2002_xB002 = 0 
events_Q2002_xB003 = 0 
events_Q2002_xB004 = 0 
events_Q2002_xB005 = 0 
events_Q2002_xB006 = 0 
events_Q2003_xB000 = 0 
events_Q2003_xB001 = 0 
events_Q2003_xB002 = 0 
events_Q2003_xB003 = 0 
events_Q2003_xB004 = 0 
events_Q2003_xB005 = 0 
events_Q2003_xB006 = 0

Something wrong?? any help would be greatly apperciated.

Thanks
Dil

Screen Shot 2022-04-07 at 11.36.31 AM
Screen Shot 2022-04-07 at 11.36.31 AM2878×1550 328 KB

2

Maybe you want:
events = h_pion_invariant_mass[iQ2][ixB]->Integral(iQ2, ixB);
or:
events = h_pion_invariant_mass[iQ2][ixB]->Integral();

1 Like
3

You must be right.Thank you for the suggestion.