#include "TH1.h"
#include "TMath.h"
#include "TF1.h"
#include "TLegend.h"
#include "TCanvas.h"


void Fit1() {

  TFile *file = new TFile("teste02.root"); 
  TH1D *MuonMassInv = file->Get("MuonMassInv"); 
  gStyle->SetOptFit();
  TF1 *backFcn = new TF1("backFcn","[0]*1/([1]*pow(x,3) + [2]*pow(x,4) + [3]*pow(x,5)) + [4]",10,200);
  backFcn->SetLineColor(kRed);
  TF1 *signalFcn = new TF1("signalFcn","(1/(2*TMath::Pi()))*[0]*[2]/((x-[1])*(x-[1])+([2]*[2]/4))",70,110);
  signalFcn->SetLineColor(kBlue);
  TF1 *fitsimple = new TF1("fitsimple","signalFcn + backFcn",10,200);

  fitsimple->SetNpx(500);
  fitsimple->SetLineWidth(4);
  fitsimple->SetLineColor(kMagenta);

  fitsimple->SetParName(0,"Constant");
  fitsimple->SetParameter(0,5e5);

  fitsimple->SetParName(1,"Mean");
  fitsimple->SetParameter(1,91.38);

  fitsimple->SetParName(2,"Sigma");
  fitsimple->SetParameter(2,2);
  
  
  fitsimple->SetParameter(3,1e9);
  fitsimple->SetParameter(4,5);
  fitsimple->SetParameter(5,0.0003);
  fitsimple->SetParameter(6,2.0e-3);
  fitsimple->SetParameter(7,-21.0);

  MuonMassInv->Fit("fitsimple","R");
  gPad->SetLogy();
  MuonMassInv->Draw("e");

  
}