FitZPeak.C

#include "TF1.h"
#include "TH1.h"
#include "TMath.h"
#include "TROOT.h"
#include "BW.C"

#include <iostream>
#include <string>

void FitZPeak(bool save = false, vector<string> formats = {".eps"}){

  gROOT->Macro("rootlogon.C");
  gStyle->SetOptFit(111111);

  std::string fname = "myZPeakCRAB.root";
  TFile *f = new TFile(fname.c_str(),"READ");
  TH1F *Z_mass;
  if (f && f->IsOpen()) {
    Z_mass = (TH1F*)f->Get("analyzeBasicPat/mumuMass");
    if (!Z_mass) {
      std::cout << "ERROR::Unable to find the histogram analyzeBasicPat/mumuMass in file " << f->GetName() << std::endl;
      return;
    }
  }
  else {
    std::cout << "ERROR::Unable to open the file " << fname << std::endl;
    return;
  }

  //float massMIN = Z_mass->GetBinLowEdge(1);
  //float massMAX = Z_mass->GetBinLowEdge(Z_mass->GetNbinsX()+1);

  float massMIN = 88.0; // 80.0
  float massMAX = 94.0; // 100.0

  ////////////////
  //For Gaussian//
  ////////////////
  /*
  TF1 *func = new TF1("mygauss",mygauss,massMIN, massMAX,3); 
  func->SetParameter(0,1.0);   func->SetParName(0,"const");  
  func->SetParameter(2,5.0);   func->SetParName(2,"sigma");  
  func->SetParameter(1,95.0);     func->SetParName(1,"mean");

  Z_mass->Fit("mygauss","QR");
  TF1 *fit = Z_mass->GetFunction("mygauss");
  */
  ////////////////////
  //For Breit-Wigner//
  ////////////////////
  
   TF1 *func = new TF1("mybw",mybw,massMIN, massMAX,3);
   func->SetParameter(0,1.0);   func->SetParName(0,"const");
   func->SetParameter(2,5.0);     func->SetParName(1,"sigma");
   func->SetParameter(1,95.0);    func->SetParName(2,"mean");
   
   Z_mass->Fit("mybw","QR");
   TF1 *fit = Z_mass->GetFunction("mybw");
  
  //////////////
  //Formatting//
  //////////////

  fit->SetLineColor(4);
  fit->SetLineWidth(3);

  Z_mass->SetMarkerStyle(20);
  Z_mass->SetMarkerSize(1.0);
  Z_mass->SetMarkerColor(2);
  Z_mass->SetLineWidth(2.0);
  Z_mass->SetXTitle("Z Mass (in GeV/c^{2})"); 
  // Z_mass->GetXaxis()->SetTitleOffset(1.0);

  //////////////
  //Processing//
  //////////////

  Z_mass->Draw("PE0");

  if (save) {
    TCanvas* c1 = (TCanvas*)gROOT->GetListOfCanvases()->At(0);
    for (auto format : formats) {
      //c1->Print (("myZmass_BWfitted"+format).c_str());
      c1->Print (("myZmass_Gausfitted"+format).c_str());
    }
  }
}