Storing the produced distribution in .root format

[m.sohail]

Here is the part of my macro. This macro produces some distribution providing an input “root” file. When I run the macro it produces me some distributions. I want to store the produced distribution in .root format. Please suggest me.

#include <TString.h>
using namespace std;
TH1F * Subtract(TH1F *data, TH1F *diboson, TH1F *wjets, TH1F *zjets, TH1F *singleTop);

void makeTrigSF_1 ()
{
   vector<string> trigger_name;
   vector<string> variables;
   //vector<string> variable_xaxis;

   variables.push_back("bjet1Pt");
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TH1F *lep3jet_MC_trig_eff = (TH1F *) ttbar[0][1]->Clone("MC_trig_eff");//MC_trig_eff
      lep3jet_MC_trig_eff->Divide(ttbar[0][0]);
      lep3jet_MC_trig_eff->Draw("SAME");
      lep3jet_MC_trig_eff->SetLineColor(kGreen);// it was green
      lep3jet_MC_trig_eff->SetLineWidth(5);
      TLegend *mylegend2 = new TLegend(.7,.75,.89,.89);
      mylegend2->SetBorderSize(0);
      mylegend2->SetTextSize(0.030);
      mylegend2->AddEntry(lep3jet_MC_trig_eff,"MC_Trigger_Efficiency","l");// for electron
      //mylegend2->AddEntry(lep3jet_MC_trig_eff,"Trigger_Scale_Factor","l");// for muon
      mylegend2->Draw("SAME");

      TH1F *SF = (TH1F *) lep3jet_trig_eff->Clone("SF_trig");// it was SF_trig
      SF->Divide(lep3jet_MC_trig_eff);
      SF->SetLineColor(kRed);
      SF->Draw("SAME");
      SF->Write();

[couet]

You need to open a new ROOT file using TFile with the option RECREATE and Write() the distributions you need to save in that ROOT file.

[m.sohail]

You mean to open a new file TFile in the same macro just before the Writing the distributions?

[couet]

Yes or open the the original TFile in UPDATE mode to allow writing in it.

[m.sohail]

This is the usuall message I am getting i.e
Error in TFile::WriteTObject: Directory hist_tot_lep.root is not writable
the hist_tot_lep.root is the input file to produce the distributions.

This is my modification:
TH1F *SF1 = new TH1F(“SF”,“my histogram”,100,-3,3);
SF->Write();

[couet]

So try to save SF1 in a new file as I suggested

[m.sohail]

As per your kind suggestion I changed SF to SF1->Write(); and got the same message as before.

[m.sohail]

Hi Couet
The “UPDATE” works for me I want to save the distributions independently. I have to save several distributions and then merge them to make new root file. Please help me in saving independently. Here is my modification:
TH1F *SF1 = new TH1F(“SF”,“my histogram”,100,-3,3);
SF1->Write();

[couet]

@m.sohail

saving independently

For that you need to make a new TFile as I told you first.