set ownership of cuts container

[u/mrichter/AliRoot.git] / PWG3 / vertexingHF / AliHFMassFitter.cxx

/**************************************************************************
 * Copyright(c) 1998-2009, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

/////////////////////////////////////////////////////////////
//
// AliHFMassFitter for the fit of invariant mass distribution
// of charmed mesons
//
// Author: C.Bianchin, chiara.bianchin@pd.infn.it
/////////////////////////////////////////////////////////////

#include <Riostream.h>
#include <TMath.h>
#include <TNtuple.h>
#include <TH1F.h>
#include <TF1.h>
#include <TList.h>
#include <TFile.h>
#include <TCanvas.h>
#include <TVirtualPad.h>
#include <TGraph.h>
#include <TVirtualFitter.h>
#include <TMinuit.h>
#include <TStyle.h>
#include <TPaveText.h>

#include "AliHFMassFitter.h"



ClassImp(AliHFMassFitter)

 //************** constructors
AliHFMassFitter::AliHFMassFitter() : 
  TNamed(),
  fhistoInvMass(0),
  fminMass(0),
  fmaxMass(0),
  fminBinMass(0),
  fmaxBinMass(0),
  fNbin(0),
  fParsSize(1),
  fNFinalPars(1),
  fFitPars(0),
  fWithBkg(0),
  ftypeOfFit4Bkg(0),
  ftypeOfFit4Sgn(0),
  ffactor(1),
  fntuParam(0),
  fMass(1.865),
  fSigmaSgn(0.012),
  fSideBands(0),
  fFixPar(0),
  fSideBandl(0),
  fSideBandr(0),
  fcounter(0),
  fContourGraph(0)
{
  // default constructor
 
  cout<<"Default constructor:"<<endl;
  cout<<"Remember to set the Histo, the Type, the FixPar"<<endl;

}

//___________________________________________________________________________

AliHFMassFitter::AliHFMassFitter (const TH1F *histoToFit, Double_t minvalue, Double_t maxvalue, Int_t rebin,Int_t fittypeb,Int_t fittypes): 
 TNamed(),
 fhistoInvMass(0),
 fminMass(0),
 fmaxMass(0),
 fminBinMass(0),
 fmaxBinMass(0),
 fNbin(0),
 fParsSize(1),
 fNFinalPars(1),
 fFitPars(0),
 fWithBkg(0),
 ftypeOfFit4Bkg(0),
 ftypeOfFit4Sgn(0),
 ffactor(1),
 fntuParam(0),
 fMass(1.865),
 fSigmaSgn(0.012),
 fSideBands(0),
 fFixPar(0),
 fSideBandl(0),
 fSideBandr(0),
 fcounter(0),
 fContourGraph(0)
{
  // standard constructor

  fhistoInvMass= (TH1F*)histoToFit->Clone("fhistoInvMass");
  fhistoInvMass->SetDirectory(0);
  fminMass=minvalue; 
  fmaxMass=maxvalue;
  if(rebin!=1) RebinMass(rebin); 
  else fNbin=(Int_t)fhistoInvMass->GetNbinsX();
  CheckRangeFit();
  ftypeOfFit4Bkg=fittypeb;
  ftypeOfFit4Sgn=fittypes;
  if(ftypeOfFit4Bkg!=0 && ftypeOfFit4Bkg!=1 && ftypeOfFit4Bkg!=2) fWithBkg=kFALSE;
  else fWithBkg=kTRUE;
  if (!fWithBkg) cout<<"Fit Histogram of Signal only"<<endl;
  else  cout<<"Type of fit For Background = "<<ftypeOfFit4Bkg<<endl;

  ComputeParSize();
  fFitPars=new Float_t[fParsSize];

  SetDefaultFixParam();

  fContourGraph=new TList();
  fContourGraph->SetOwner();

}


AliHFMassFitter::AliHFMassFitter(const AliHFMassFitter &mfit):
  TNamed(),
  fhistoInvMass(mfit.fhistoInvMass),
  fminMass(mfit.fminMass),
  fmaxMass(mfit.fmaxMass),
  fminBinMass(mfit.fminBinMass),
  fmaxBinMass(mfit.fmaxBinMass),
  fNbin(mfit.fNbin),
  fParsSize(mfit.fParsSize),
  fNFinalPars(mfit.fNFinalPars),
  fFitPars(0),
  fWithBkg(mfit.fWithBkg),
  ftypeOfFit4Bkg(mfit.ftypeOfFit4Bkg),
  ftypeOfFit4Sgn(mfit.ftypeOfFit4Sgn),
  ffactor(mfit.ffactor),
  fntuParam(mfit.fntuParam),
  fMass(mfit.fMass),
  fSigmaSgn(mfit.fSigmaSgn),
  fSideBands(mfit.fSideBands),
  fFixPar(0),
  fSideBandl(mfit.fSideBandl),
  fSideBandr(mfit.fSideBandr),
  fcounter(mfit.fcounter),
  fContourGraph(mfit.fContourGraph)
{
  //copy constructor
  
  if(mfit.fParsSize > 0){
    fFitPars=new Float_t[fParsSize];
    fFixPar=new Bool_t[fNFinalPars];
    memcpy(fFitPars,mfit.fFitPars,mfit.fParsSize*sizeof(Float_t));
    memcpy(fFixPar,mfit.fFixPar,mfit.fNFinalPars*sizeof(Bool_t));
  }

}

//_________________________________________________________________________

AliHFMassFitter::~AliHFMassFitter() {

  //destructor

  cout<<"AliHFMassFitter destructor called"<<endl;

  delete fhistoInvMass;

  delete fntuParam;

  delete[] fFitPars;
  
  delete[] fFixPar;
  
  fcounter = 0;
}

//_________________________________________________________________________

AliHFMassFitter& AliHFMassFitter::operator=(const AliHFMassFitter &mfit){

  //assignment operator

  if(&mfit == this) return *this;
  fhistoInvMass= mfit.fhistoInvMass;
  fminMass= mfit.fminMass;
  fmaxMass= mfit.fmaxMass;
  fNbin= mfit.fNbin;
  fParsSize= mfit.fParsSize;
  fWithBkg= mfit.fWithBkg;
  ftypeOfFit4Bkg= mfit.ftypeOfFit4Bkg;
  ftypeOfFit4Sgn= mfit.ftypeOfFit4Sgn;
  ffactor= mfit.ffactor;
  fntuParam= mfit.fntuParam;
  fMass= mfit.fMass;
  fSigmaSgn= mfit.fSigmaSgn;
  fSideBands= mfit.fSideBands;
  fSideBandl= mfit.fSideBandl;
  fSideBandr= mfit.fSideBandr;
  fcounter= mfit.fcounter;
  fContourGraph= mfit.fContourGraph;

  if(mfit.fParsSize > 0){
    delete[] fFitPars;
    
    fFitPars=new Float_t[fParsSize];
    memcpy(fFitPars,mfit.fFitPars,mfit.fParsSize*sizeof(Float_t));

    delete[] fFixPar;
    
    fFixPar=new Bool_t[fNFinalPars];
    memcpy(fFixPar,mfit.fFixPar,mfit.fNFinalPars*sizeof(Float_t));
  }

  return *this;
}

//************ tools & settings

//__________________________________________________________________________

void AliHFMassFitter::ComputeNFinalPars() {

  //compute the number of parameters of the total (signal+bgk) function
  cout<<"Info:ComputeNFinalPars... ";
  switch (ftypeOfFit4Bkg) {//npar background func
  case 0:
    fNFinalPars=2;
    break;
  case 1:
    fNFinalPars=2;
    break;
  case 2:
    fNFinalPars=3;
    break;
  case 3:
    fNFinalPars=1;
    break;
  default:
    cout<<"Error in computing fNFinalPars: check ftypeOfFit4Bkg"<<endl;
    break;
  }

  fNFinalPars+=3; //gaussian signal
  cout<<": "<<fNFinalPars<<endl;
}
//__________________________________________________________________________

void AliHFMassFitter::ComputeParSize() {

  //compute the size of the parameter array and set the data member

  switch (ftypeOfFit4Bkg) {//npar background func
  case 0:
    fParsSize = 2*3;
    break;
  case 1:
    fParsSize = 2*3;
    break;
  case 2:
    fParsSize = 3*3;
    break;
  case 3:
    fParsSize = 1*3;
    break;
  default:
    cout<<"Error in computing fParsSize: check ftypeOfFit4Bkg"<<endl;
    break;
  }

  fParsSize += 3; // npar refl
  fParsSize += 3; // npar signal gaus

  fParsSize*=2;   // add errors
  cout<<"Parameters array size "<<fParsSize<<endl;
}

//___________________________________________________________________________
void AliHFMassFitter::SetDefaultFixParam(){

  //Set default values for fFixPar (only total integral fixed)

  ComputeNFinalPars();
  fFixPar=new Bool_t[fNFinalPars];

  fFixPar[0]=kTRUE; //default: IntTot fixed
  cout<<"Parameter 0 is fixed"<<endl;
  for(Int_t i=1;i<fNFinalPars;i++){
    fFixPar[i]=kFALSE;
  }

}

//___________________________________________________________________________
Bool_t AliHFMassFitter::SetFixThisParam(Int_t thispar,Bool_t fixpar){

  //set the value (kFALSE or kTRUE) of one element of fFixPar
  //return kFALSE if something wrong

  if(thispar>=fNFinalPars) {
    cout<<"Error! Parameter out of bounds! Max is "<<fNFinalPars-1<<endl;
    return kFALSE;
  }
  if(!fFixPar){
    cout<<"Initializing fFixPar...";
    SetDefaultFixParam();
    cout<<" done."<<endl;
  }

  fFixPar[thispar]=fixpar;
  if(fixpar)cout<<"Parameter "<<thispar<<" is now fixed"<<endl;
  else cout<<"Parameter "<<thispar<<" is now free"<<endl;
  return kTRUE;
}

//___________________________________________________________________________
Bool_t AliHFMassFitter::GetFixThisParam(Int_t thispar)const{
  //return the value of fFixPar[thispar]
  if(thispar>=fNFinalPars) {
    cout<<"Error! Parameter out of bounds! Max is "<<fNFinalPars-1<<endl;
    return kFALSE;
  }
  if(!fFixPar) {
    cout<<"Error! Parameters to be fixed still not set"<<endl;
    return kFALSE;

  }
  return fFixPar[thispar];
 
}

//___________________________________________________________________________
void AliHFMassFitter::SetHisto(const TH1F *histoToFit){

  fhistoInvMass = new TH1F(*histoToFit);
  fhistoInvMass->SetDirectory(0);
  //cout<<"SetHisto pointer "<<fhistoInvMass<<endl;
}

//___________________________________________________________________________

void AliHFMassFitter::SetType(Int_t fittypeb, Int_t fittypes) {
  
  //set the type of fit to perform for signal and background
  
  ftypeOfFit4Bkg = fittypeb; 
  ftypeOfFit4Sgn = fittypes; 
  
  ComputeParSize();
  fFitPars = new Float_t[fParsSize];
  
  SetDefaultFixParam();
}

//___________________________________________________________________________

void AliHFMassFitter::Reset() {

  //delete the histogram and reset the mean and sigma to default

  cout<<"Reset called: delete histogram, set mean value to 1.85 and sigma to 0.012"<<endl;
  fMass=1.85;
  fSigmaSgn=0.012;
  cout<<"Reset "<<fhistoInvMass<<endl;
  delete fhistoInvMass;
}

//_________________________________________________________________________

void AliHFMassFitter::InitNtuParam(char *ntuname) {

  // Create ntuple to keep fit parameters

  fntuParam=0;
  fntuParam=new TNtuple(ntuname,"Contains fit parameters","intbkg1:slope1:conc1:intGB:meanGB:sigmaGB:intbkg2:slope2:conc2:inttot:slope3:conc3:intsgn:meansgn:sigmasgn:intbkg1Err:slope1Err:conc1Err:intGBErr:meanGBErr:sigmaGBErr:intbkg2Err:slope2Err:conc2Err:inttotErr:slope3Err:conc3Err:intsgnErr:meansgnErr:sigmasgnErr");
  
}

//_________________________________________________________________________

void AliHFMassFitter::FillNtuParam() {
  // Fill ntuple with fit parameters

  Float_t nothing=0.;

  if (ftypeOfFit4Bkg==2) {
      fntuParam->SetBranchAddress("intbkg1",&fFitPars[0]);
      fntuParam->SetBranchAddress("slope1",&fFitPars[1]);
      fntuParam->SetBranchAddress("conc1",&fFitPars[2]);
      fntuParam->SetBranchAddress("intGB",&fFitPars[3]);
      fntuParam->SetBranchAddress("meanGB",&fFitPars[4]);
      fntuParam->SetBranchAddress("sigmaGB",&fFitPars[5]);
      fntuParam->SetBranchAddress("intbkg2",&fFitPars[6]);
      fntuParam->SetBranchAddress("slope2",&fFitPars[7]);
      fntuParam->SetBranchAddress("conc2",&fFitPars[8]);
      fntuParam->SetBranchAddress("inttot",&fFitPars[9]);
      fntuParam->SetBranchAddress("slope3",&fFitPars[10]);
      fntuParam->SetBranchAddress("conc3",&fFitPars[11]);
      fntuParam->SetBranchAddress("intsgn",&fFitPars[12]);
      fntuParam->SetBranchAddress("meansgn",&fFitPars[13]);
      fntuParam->SetBranchAddress("sigmasgn",&fFitPars[14]);

      fntuParam->SetBranchAddress("intbkg1Err",&fFitPars[15]);
      fntuParam->SetBranchAddress("slope1Err",&fFitPars[16]);
      fntuParam->SetBranchAddress("conc1Err",&fFitPars[17]);
      fntuParam->SetBranchAddress("intGBErr",&fFitPars[18]);
      fntuParam->SetBranchAddress("meanGBErr",&fFitPars[19]);
      fntuParam->SetBranchAddress("sigmaGBErr",&fFitPars[20]);
      fntuParam->SetBranchAddress("intbkg2Err",&fFitPars[21]);
      fntuParam->SetBranchAddress("slope2Err",&fFitPars[22]);
      fntuParam->SetBranchAddress("conc2Err",&fFitPars[23]);
      fntuParam->SetBranchAddress("inttotErr",&fFitPars[24]);
      fntuParam->SetBranchAddress("slope3Err",&fFitPars[25]);
      fntuParam->SetBranchAddress("conc3Err",&fFitPars[26]);
      fntuParam->SetBranchAddress("intsgnErr",&fFitPars[27]);
      fntuParam->SetBranchAddress("meansgnErr",&fFitPars[28]);
      fntuParam->SetBranchAddress("sigmasgnErr",&fFitPars[29]);
    
  } else {
    
    if(ftypeOfFit4Bkg==3){
      fntuParam->SetBranchAddress("intbkg1",&fFitPars[0]);
      fntuParam->SetBranchAddress("slope1",&nothing);
      fntuParam->SetBranchAddress("conc1",&nothing);
      fntuParam->SetBranchAddress("intGB",&fFitPars[1]);
      fntuParam->SetBranchAddress("meanGB",&fFitPars[2]);
      fntuParam->SetBranchAddress("sigmaGB",&fFitPars[3]);
      fntuParam->SetBranchAddress("intbkg2",&fFitPars[4]);
      fntuParam->SetBranchAddress("slope2",&nothing);
      fntuParam->SetBranchAddress("conc2",&nothing);
      fntuParam->SetBranchAddress("inttot",&fFitPars[6]);
      fntuParam->SetBranchAddress("slope3",&nothing);
      fntuParam->SetBranchAddress("conc3",&nothing);
      fntuParam->SetBranchAddress("intsgn",&fFitPars[6]);
      fntuParam->SetBranchAddress("meansgn",&fFitPars[7]);
      fntuParam->SetBranchAddress("sigmasgn",&fFitPars[8]);

      fntuParam->SetBranchAddress("intbkg1Err",&fFitPars[9]);
      fntuParam->SetBranchAddress("slope1Err",&nothing);
      fntuParam->SetBranchAddress("conc1Err",&nothing);
      fntuParam->SetBranchAddress("intGBErr",&fFitPars[10]);
      fntuParam->SetBranchAddress("meanGBErr",&fFitPars[11]);
      fntuParam->SetBranchAddress("sigmaGBErr",&fFitPars[12]);
      fntuParam->SetBranchAddress("intbkg2Err",&fFitPars[13]);
      fntuParam->SetBranchAddress("slope2Err",&nothing);
      fntuParam->SetBranchAddress("conc2Err",&nothing);
      fntuParam->SetBranchAddress("inttotErr",&fFitPars[15]);
      fntuParam->SetBranchAddress("slope3Err",&nothing);
      fntuParam->SetBranchAddress("conc3Err",&nothing);
      fntuParam->SetBranchAddress("intsgnErr",&fFitPars[15]);
      fntuParam->SetBranchAddress("meansgnErr",&fFitPars[16]);
      fntuParam->SetBranchAddress("sigmasgnErr",&fFitPars[17]);

    }
    else{
      fntuParam->SetBranchAddress("intbkg1",&fFitPars[0]);
      fntuParam->SetBranchAddress("slope1",&fFitPars[1]);
      fntuParam->SetBranchAddress("conc1",&nothing);
      fntuParam->SetBranchAddress("intGB",&fFitPars[2]);
      fntuParam->SetBranchAddress("meanGB",&fFitPars[3]);
      fntuParam->SetBranchAddress("sigmaGB",&fFitPars[4]);
      fntuParam->SetBranchAddress("intbkg2",&fFitPars[5]);
      fntuParam->SetBranchAddress("slope2",&fFitPars[6]);
      fntuParam->SetBranchAddress("conc2",&nothing);
      fntuParam->SetBranchAddress("inttot",&fFitPars[7]);
      fntuParam->SetBranchAddress("slope3",&fFitPars[8]);
      fntuParam->SetBranchAddress("conc3",&nothing);
      fntuParam->SetBranchAddress("intsgn",&fFitPars[9]);
      fntuParam->SetBranchAddress("meansgn",&fFitPars[10]);
      fntuParam->SetBranchAddress("sigmasgn",&fFitPars[11]);

      fntuParam->SetBranchAddress("intbkg1Err",&fFitPars[12]);
      fntuParam->SetBranchAddress("slope1Err",&fFitPars[13]);
      fntuParam->SetBranchAddress("conc1Err",&nothing);
      fntuParam->SetBranchAddress("intGBErr",&fFitPars[14]);
      fntuParam->SetBranchAddress("meanGBErr",&fFitPars[15]);
      fntuParam->SetBranchAddress("sigmaGBErr",&fFitPars[16]);
      fntuParam->SetBranchAddress("intbkg2Err",&fFitPars[17]);
      fntuParam->SetBranchAddress("slope2Err",&fFitPars[18]);
      fntuParam->SetBranchAddress("conc2Err",&nothing);
      fntuParam->SetBranchAddress("inttotErr",&fFitPars[19]);
      fntuParam->SetBranchAddress("slope3Err",&fFitPars[20]);
      fntuParam->SetBranchAddress("conc3Err",&nothing);
      fntuParam->SetBranchAddress("intsgnErr",&fFitPars[21]);
      fntuParam->SetBranchAddress("meansgnErr",&fFitPars[22]);
      fntuParam->SetBranchAddress("sigmasgnErr",&fFitPars[23]);
    }
     
  }
  fntuParam->TTree::Fill();
}

//_________________________________________________________________________

TNtuple* AliHFMassFitter::NtuParamOneShot(char *ntuname){
  // Create, fill and return ntuple with fit parameters

  InitNtuParam(ntuname);
  FillNtuParam();
  return fntuParam;
}
//_________________________________________________________________________

void AliHFMassFitter::RebinMass(Int_t bingroup){
  // Rebin invariant mass histogram

  if(!fhistoInvMass){
    cout<<"Histogram not set"<<endl;
    return;
  }
  Int_t nbinshisto=fhistoInvMass->GetNbinsX();
  if(bingroup<1){
    cout<<"Error! Cannot group "<<bingroup<<" bins\n";
    fNbin=nbinshisto;
    cout<<"Kept original number of bins: "<<fNbin<<endl;
  } else{
   
    while(nbinshisto%bingroup != 0) {
      bingroup--;
    }
    cout<<"Group "<<bingroup<<" bins"<<endl;
    fhistoInvMass->Rebin(bingroup);
    fNbin = fhistoInvMass->GetNbinsX();
    cout<<"New number of bins: "<<fNbin<<endl;
  } 
       
}

//************* fit

//___________________________________________________________________________

Double_t AliHFMassFitter::FitFunction4MassDistr (Double_t *x, Double_t *par){
  // Fit function for signal+background


  //exponential or linear fit
  //
  // par[0] = tot integral
  // par[1] = slope
  // par[2] = gaussian integral
  // par[3] = gaussian mean
  // par[4] = gaussian sigma
  
  Double_t total,bkg=0,sgn=0;
  
  if (ftypeOfFit4Bkg==0 || ftypeOfFit4Bkg==1) {
    if(ftypeOfFit4Sgn == 0) {

      Double_t parbkg[2] = {par[0]-par[2], par[1]};
      bkg = FitFunction4Bkg(x,parbkg);
    }
    if(ftypeOfFit4Sgn == 1) {
      Double_t parbkg[5] = {par[2],par[3],ffactor*par[4],par[0]-2*par[2], par[1]};
      bkg = FitFunction4Bkg(x,parbkg);
    }

    sgn = FitFunction4Sgn(x,&par[2]);  

  }

  //polynomial fit

    // par[0] = tot integral
    // par[1] = coef1
    // par[2] = coef2
    // par[3] = gaussian integral
    // par[4] = gaussian mean
    // par[5] = gaussian sigma

  if (ftypeOfFit4Bkg==2) {
    
    if(ftypeOfFit4Sgn == 0) {
      
      Double_t parbkg[3] = {par[0]-par[3], par[1], par[2]};
      bkg = FitFunction4Bkg(x,parbkg);
    }
    if(ftypeOfFit4Sgn == 1) {
      
      Double_t parbkg[6] = {par[3],par[4],ffactor*par[5],par[0]-2*par[3], par[1], par[2]};
     bkg = FitFunction4Bkg(x,parbkg);
    }
    
    sgn = FitFunction4Sgn(x,&par[3]);
  }

  if (ftypeOfFit4Bkg==3) {
   
    if(ftypeOfFit4Sgn == 0) {
	bkg=FitFunction4Bkg(x,par);
	sgn=FitFunction4Sgn(x,&par[1]);
    }
    if(ftypeOfFit4Sgn == 1) {
      Double_t parbkg[4]={par[1],par[2],ffactor*par[3],par[0]};
      bkg=FitFunction4Bkg(x,parbkg);
      sgn=FitFunction4Sgn(x,&par[1]);
    }
  }

  total = bkg + sgn;
  
  return  total;
}

//_________________________________________________________________________
Double_t AliHFMassFitter::FitFunction4Sgn (Double_t *x, Double_t *par){
  // Fit function for the signal

  //gaussian = A/(sigma*sqrt(2*pi))*exp(-(x-mean)^2/2/sigma^2)
  //Par:
  // * [0] = integralSgn
  // * [1] = mean
  // * [2] = sigma
  //gaussian = [0]/TMath::Sqrt(2.*TMath::Pi())/[2]*exp[-(x-[1])*(x-[1])/(2*[2]*[2])]

  return par[0]/TMath::Sqrt(2.*TMath::Pi())/par[2]*TMath::Exp(-(x[0]-par[1])*(x[0]-par[1])/2./par[2]/par[2]);

}

//__________________________________________________________________________

Double_t AliHFMassFitter::FitFunction4Bkg (Double_t *x, Double_t *par){
  // Fit function for the background

  Double_t maxDeltaM = 4.*fSigmaSgn;
  if(fSideBands && TMath::Abs(x[0]-fMass) < maxDeltaM) {
    TF1::RejectPoint();
    return 0;
  }
  Int_t firstPar=0;
  Double_t gaus2=0,total=-1;
  if(ftypeOfFit4Sgn == 1){
    firstPar=3;
    //gaussian = A/(sigma*sqrt(2*pi))*exp(-(x-mean)^2/2/sigma^2)
    //Par:
    // * [0] = integralSgn
    // * [1] = mean
    // * [2] = sigma
    //gaussian = [0]/TMath::Sqrt(2.*TMath::Pi())/[2]*exp[-(x-[1])*(x-[1])/(2*[2]*[2])]
    gaus2 = FitFunction4Sgn(x,par);
  }

  switch (ftypeOfFit4Bkg){
  case 0:
    //exponential
    //exponential = A*exp(B*x) -> integral(exponential)=A/B*exp(B*x)](min,max)
    //-> A = B*integral/(exp(B*max)-exp(B*min)) where integral can be written
    //as integralTot- integralGaus (=par [2])
    //Par:
    // * [0] = integralBkg;
    // * [1] = B;
    //exponential = [1]*[0]/(exp([1]*max)-exp([1]*min))*exp([1]*x)
    total = par[0+firstPar]*par[1+firstPar]/(TMath::Exp(par[1+firstPar]*fmaxMass)-TMath::Exp(par[1+firstPar]*fminMass))*TMath::Exp(par[1+firstPar]*x[0]);
    break;
  case 1:
    //linear
    //y=a+b*x -> integral = a(max-min)+1/2*b*(max^2-min^2) -> a = (integral-1/2*b*(max^2-min^2))/(max-min)=integral/(max-min)-1/2*b*(max+min)
    // * [0] = integralBkg;
    // * [1] = b;
    total= par[0+firstPar]/(fmaxMass-fminMass)+par[1+firstPar]*(x[0]-0.5*(fmaxMass+fminMass));
    break;
  case 2:
    //polynomial
    //y=a+b*x+c*x**2 -> integral = a(max-min) + 1/2*b*(max^2-min^2) +
    //+ 1/3*c*(max^3-min^3) -> 
    //a = (integral-1/2*b*(max^2-min^2)-1/3*c*(max^3-min^3))/(max-min)
    // * [0] = integralBkg;
    // * [1] = b;
    // * [2] = c;
    total = par[0+firstPar]/(fmaxMass-fminMass)+par[1]*(x[0]-0.5*(fmaxMass+fminMass))+par[2+firstPar]*(x[0]*x[0]-1/3.*(fmaxMass*fmaxMass*fmaxMass-fminMass*fminMass*fminMass)/(fmaxMass-fminMass));
    break;
  case 3:
    total=par[0+firstPar];
    break;
//   default:
//     Types of Fit Functions for Background:
//     * 0 = exponential;
//     * 1 = linear;
//     * 2 = polynomial 2nd order
//     * 3 = no background"<<endl;

  }
  return total+gaus2;
}

//__________________________________________________________________________
Bool_t AliHFMassFitter::SideBandsBounds(){

  //determines the ranges of the side bands

  if (fNbin==0) fNbin=fhistoInvMass->GetNbinsX();
  Double_t minHisto=fhistoInvMass->GetBinLowEdge(1);
  Double_t maxHisto=fhistoInvMass->GetBinLowEdge(fNbin+1);

  Double_t sidebandldouble,sidebandrdouble;
  Bool_t leftok=kFALSE, rightok=kFALSE;

  if(fMass-fminMass < 0 || fmaxMass-fMass <0) {
    cout<<"Left limit of range > mean or right limit of range < mean: change left/right limit or initial mean value"<<endl;
    return kFALSE;
  } 
  
  //histo limit = fit function limit
  if((TMath::Abs(fminMass-minHisto) < 1e6 || TMath::Abs(fmaxMass - maxHisto) < 1e6) && (fMass-4.*fSigmaSgn-fminMass) < 1e6){
    Double_t coeff = (fMass-fminMass)/fSigmaSgn;
    sidebandldouble=(fMass-0.5*coeff*fSigmaSgn);
    sidebandrdouble=(fMass+0.5*coeff*fSigmaSgn);
    cout<<"Changed number of sigma from 4 to "<<0.5*coeff<<" for the estimation of the side bands"<<endl;
    if (coeff<3) cout<<"Side bands inside 3 sigma, may be better use ftypeOfFit4Bkg = 3 (only signal)"<<endl;
    if (coeff<2) {
      cout<<"Side bands inside 2 sigma. Change mode: ftypeOfFit4Bkg = 3"<<endl;
      ftypeOfFit4Bkg=3;
      //set binleft and right without considering SetRangeFit- anyway no bkg!
      sidebandldouble=(fMass-4.*fSigmaSgn);
      sidebandrdouble=(fMass+4.*fSigmaSgn);
    }
  }
  else {
    sidebandldouble=(fMass-4.*fSigmaSgn);
    sidebandrdouble=(fMass+4.*fSigmaSgn);
  }

  cout<<"Left side band ";
  Double_t tmp=0.;
  tmp=sidebandldouble;
  //calculate bin corresponding to fSideBandl
  fSideBandl=fhistoInvMass->FindBin(sidebandldouble);
  if (sidebandldouble >= fhistoInvMass->GetBinCenter(fSideBandl)) fSideBandl++;
  sidebandldouble=fhistoInvMass->GetBinLowEdge(fSideBandl);
  
  if(TMath::Abs(tmp-sidebandldouble) > 1e-6){
    cout<<tmp<<" is not allowed, changing it to the nearest value allowed: ";
    leftok=kTRUE;
  }
  cout<<sidebandldouble<<" (bin "<<fSideBandl<<")"<<endl;

  cout<<"Right side band ";
  tmp=sidebandrdouble;
  //calculate bin corresponding to fSideBandr
  fSideBandr=fhistoInvMass->FindBin(sidebandrdouble);
  if (sidebandrdouble < fhistoInvMass->GetBinCenter(fSideBandr)) fSideBandr--;
  sidebandrdouble=fhistoInvMass->GetBinLowEdge(fSideBandr+1);

  if(TMath::Abs(tmp-sidebandrdouble) > 1e-6){
    cout<<tmp<<" is not allowed, changing it to the nearest value allowed: ";
    rightok=kTRUE;
  }
  cout<<sidebandrdouble<<" (bin "<<fSideBandr<<")"<<endl;
  if (fSideBandl==0 || fSideBandr==fNbin) {
    cout<<"Error! Range too little"; 
    return kFALSE;
  }
  return kTRUE;
}

//__________________________________________________________________________

void AliHFMassFitter::GetSideBandsBounds(Int_t &left, Int_t &right) const{
  
  // get the range of the side bands

  if (fSideBandl==0 && fSideBandr==0){
    cout<<"Use MassFitter method first"<<endl;
    return;
  }
  left=fSideBandl;
  right=fSideBandr;
}

//__________________________________________________________________________
Bool_t AliHFMassFitter::CheckRangeFit(){
  //check if the limit of the range correspond to the limit of bins. If not reset the limit to the nearer value which satisfy this condition

  if (!fhistoInvMass) {
    cout<<"No histogram to fit! SetHisto(TH1F* h) before! "<<endl;
    return kFALSE;
  }
  Bool_t leftok=kFALSE, rightok=kFALSE;
  Int_t nbins=fhistoInvMass->GetNbinsX();
  Double_t minhisto=fhistoInvMass->GetBinLowEdge(1), maxhisto=fhistoInvMass->GetBinLowEdge(nbins+1);

  //check if limits are inside histogram range

  if( fminMass-minhisto < 0. ) {
    cout<<"Out of histogram left bound! Setting to "<<minhisto<<endl;
    fminMass=minhisto;
  }
  if( fmaxMass-maxhisto > 0. ) {
    cout<<"Out of histogram right bound! Setting to"<<maxhisto<<endl;
    fmaxMass=maxhisto;
  }

  Double_t tmp=0.;
  tmp=fminMass;
  //calculate bin corresponding to fminMass
  fminBinMass=fhistoInvMass->FindBin(fminMass);
  if (fminMass >= fhistoInvMass->GetBinCenter(fminBinMass)) fminBinMass++;
  fminMass=fhistoInvMass->GetBinLowEdge(fminBinMass);
  if(TMath::Abs(tmp-fminMass) > 1e-6){
    cout<<"Left bound "<<tmp<<" is not allowed, changing it to the nearest value allowed: "<<fminMass<<endl;
    leftok=kTRUE;
  }
 
  tmp=fmaxMass;
  //calculate bin corresponding to fmaxMass
  fmaxBinMass=fhistoInvMass->FindBin(fmaxMass);
  if (fmaxMass < fhistoInvMass->GetBinCenter(fmaxBinMass)) fmaxBinMass--;
  fmaxMass=fhistoInvMass->GetBinLowEdge(fmaxBinMass+1);
  if(TMath::Abs(tmp-fmaxMass) > 1e-6){
    cout<<"Right bound "<<tmp<<" is not allowed, changing it to the nearest value allowed: "<<fmaxMass<<endl;
    rightok=kTRUE;
  }

  return (leftok && rightok);
 
}

//__________________________________________________________________________

Bool_t AliHFMassFitter::MassFitter(Bool_t draw){  
  // Main method of the class: performs the fit of the histogram
  
  //Set default fitter Minuit in order to use gMinuit in the contour plots    
  TVirtualFitter::SetDefaultFitter("Minuit");


  Bool_t isBkgOnly=kFALSE;

  Int_t fit1status=RefitWithBkgOnly(kFALSE);
  if(fit1status){
    Int_t checkinnsigma=4;
    Double_t range[2]={fMass-checkinnsigma*fSigmaSgn,fMass+checkinnsigma*fSigmaSgn};
    TF1* func=GetHistoClone()->GetFunction("funcbkgonly");
    Double_t intUnderFunc=func->Integral(range[0],range[1]);
    Double_t intUnderHisto=fhistoInvMass->Integral(fhistoInvMass->FindBin(range[0]),fhistoInvMass->FindBin(range[1]),"width");
    cout<<"Pick zone: IntFunc = "<<intUnderFunc<<"; IntHist = "<<intUnderHisto<<"\tDiff = "<<intUnderHisto-intUnderFunc<<"\tRelDiff = "<<(intUnderHisto-intUnderFunc)/intUnderFunc<<endl;
    Double_t diffUnderPick=(intUnderHisto-intUnderFunc);
    intUnderFunc=func->Integral(fminMass,fminMass+checkinnsigma*fSigmaSgn);
    intUnderHisto=fhistoInvMass->Integral(fhistoInvMass->FindBin(fminMass),fhistoInvMass->FindBin(fminMass+checkinnsigma*fSigmaSgn),"width");
    cout<<"Band (l) zone: IntFunc = "<<intUnderFunc<<"; IntHist = "<<intUnderHisto<<"\tDiff = "<<intUnderHisto-intUnderFunc<<"\tRelDiff = "<<(intUnderHisto-intUnderFunc)/intUnderFunc<<endl;
    Double_t diffUnderBands=(intUnderHisto-intUnderFunc);
    Double_t relDiff=diffUnderPick/diffUnderBands;
    cout<<"Relative difference = "<<relDiff<<endl;
    if(TMath::Abs(relDiff) < 1) isBkgOnly=kTRUE;
    else{
      cout<<"Relative difference = "<<relDiff<<": I suppose there is some signal, continue with total fit!"<<endl;
    }
  }
  if(isBkgOnly) {
    cout<<"INFO!! The histogram contains only background"<<endl;
    if(draw)DrawFit();

    //increase counter of number of fits done
    fcounter++;

    return kTRUE;
  }

  Int_t bkgPar = fNFinalPars-3; //background function's number of parameters

  cout<<"fNFinalPars = "<<fNFinalPars<<"\tbkgPar = "<<bkgPar<<endl;


  TString listname="contourplot";
  listname+=fcounter;
  if(!fContourGraph){  
    fContourGraph=new TList();
    fContourGraph->SetOwner();
  }

  fContourGraph->SetName(listname);


  //function names
  TString bkgname="funcbkg";
  TString bkg1name="funcbkg1";
  TString massname="funcmass";

  //Total integral
  Double_t totInt = fhistoInvMass->Integral(fminBinMass,fmaxBinMass, "width");
  //cout<<"Here tot integral is = "<<totInt<<"; integral in whole range is "<<fhistoInvMass->Integral("width")<<endl;
  fSideBands = kTRUE;
  Double_t width=fhistoInvMass->GetBinWidth(8);
  //cout<<"fNbin = "<<fNbin<<endl;
  if (fNbin==0) fNbin=fhistoInvMass->GetNbinsX();

  Bool_t ok=SideBandsBounds();
  if(!ok) return kFALSE;
  
  //sidebands integral - first approx (from histo)
  Double_t sideBandsInt=(Double_t)fhistoInvMass->Integral(1,fSideBandl,"width") + (Double_t)fhistoInvMass->Integral(fSideBandr,fNbin,"width");
  cout<<"------nbin = "<<fNbin<<"\twidth = "<<width<<"\tbinleft = "<<fSideBandl<<"\tbinright = "<<fSideBandr<<endl;
  cout<<"------sideBandsInt - first approx = "<<sideBandsInt<<endl;
  if (sideBandsInt<=0) {
    cout<<"! sideBandsInt <=0. There's a problem, cannot start the fit"<<endl;
    return kFALSE;
  }
  
  /*Fit Bkg*/


  TF1 *funcbkg = new TF1(bkgname.Data(),this,&AliHFMassFitter::FitFunction4Bkg,fminMass,fmaxMass,bkgPar,"AliHFMassFitter","FitFunction4Bkg");
  cout<<"Function name = "<<funcbkg->GetName()<<endl<<endl;

  funcbkg->SetLineColor(2); //red

  //first fit for bkg: approx bkgint
 
  switch (ftypeOfFit4Bkg) {
  case 0: //gaus+expo
    funcbkg->SetParNames("BkgInt","Slope"); 
    funcbkg->SetParameters(sideBandsInt,-2.); 
    break;
  case 1:
    funcbkg->SetParNames("BkgInt","Slope");
    funcbkg->SetParameters(sideBandsInt,-100.); 
    break;
  case 2:
    funcbkg->SetParNames("BkgInt","Coef1","Coef2");
    funcbkg->SetParameters(sideBandsInt,-10.,5);
    break;
  case 3:
    if(ftypeOfFit4Sgn==0){
      funcbkg->SetParNames("Const");
      funcbkg->SetParameter(0,0.);
      funcbkg->FixParameter(0,0.);
    }
    break;
  default:
    cout<<"Wrong choise of ftypeOfFit4Bkg ("<<ftypeOfFit4Bkg<<")"<<endl;
    return kFALSE;
    break;
  }
  cout<<"\nBACKGROUND FIT - only combinatorial"<<endl;
  Int_t ftypeOfFit4SgnBkp=ftypeOfFit4Sgn;
  
  Double_t intbkg1=0,slope1=0,conc1=0;
  //if only signal and reflection: skip
  if (!(ftypeOfFit4Bkg==3 && ftypeOfFit4Sgn==1)) {
    ftypeOfFit4Sgn=0;
    fhistoInvMass->Fit(bkgname.Data(),"R,L,E,0");
   
    for(Int_t i=0;i<bkgPar;i++){
      fFitPars[i]=funcbkg->GetParameter(i);
      //cout<<i<<"\t"<<funcbkg->GetParameter(i)<<"\t";
      fFitPars[fNFinalPars+2*bkgPar+3+i]= funcbkg->GetParError(i);
      //cout<<fNFinalPars+2*bkgPar+3+i<<"\t"<< funcbkg->GetParError(i)<<endl;
    }
    fSideBands = kFALSE;
    //intbkg1 = funcbkg->GetParameter(0);

    intbkg1 = funcbkg->Integral(fminMass,fmaxMass);
    if(ftypeOfFit4Bkg!=3) slope1 = funcbkg->GetParameter(1);
    if(ftypeOfFit4Bkg==2) conc1 = funcbkg->GetParameter(2);
    //cout<<"First fit: \nintbkg1 = "<<intbkg1<<"\t(Compare with par0 = "<<funcbkg->GetParameter(0)<<")\nslope1= "<<slope1<<"\nconc1 = "<<conc1<<endl;
  } 
  else cout<<"\t\t//"<<endl;
  
  ftypeOfFit4Sgn=ftypeOfFit4SgnBkp;
  TF1 *funcbkg1=0;
  if (ftypeOfFit4Sgn == 1) {
    cout<<"\nBACKGROUND FIT WITH REFLECTION"<<endl;
    bkgPar+=3;
    
    //cout<<"fNFinalPars = "<<fNFinalPars<<"\tbkgPar = "<<bkgPar<<endl;

    funcbkg1 = new TF1(bkg1name.Data(),this,&AliHFMassFitter::FitFunction4Bkg,fminMass,fmaxMass,bkgPar,"AliHFMassFitter","FitFunction4Bkg");
    cout<<"Function name = "<<funcbkg1->GetName()<<endl;

    funcbkg1->SetLineColor(2); //red

    if(ftypeOfFit4Bkg==2){
      cout<<"*** Polynomial Fit ***"<<endl;
      funcbkg1->SetParNames("IntGB","MeanGB","SigmaGB","BkgInt","Coef1","Coef2");
      funcbkg1->SetParameters(0.5*(totInt-intbkg1),fMass,ffactor*fSigmaSgn,intbkg1,slope1,conc1);

      //cout<<"Parameters set to: "<<0.5*(totInt-intbkg1)<<"\t"<<fMass<<"\t"<<ffactor*fSigmaSgn<<"\t"<<intbkg1<<"\t"<<slope1<<"\t"<<conc1<<"\t"<<endl;
      //cout<<"Limits: ("<<fminMass<<","<<fmaxMass<<")\tnPar = "<<bkgPar<<"\tgsidebands = "<<fSideBands<<endl;
    } else{
      if(ftypeOfFit4Bkg==3) //no background: gaus sign+ gaus broadened
	{
	  cout<<"*** No background Fit ***"<<endl;
	  funcbkg1->SetParNames("IntGB","MeanGB","SigmaGB","Const");
	  funcbkg1->SetParameters(0.5*totInt,fMass,ffactor*fSigmaSgn,0.); 
	  funcbkg1->FixParameter(3,0.);
	} else{ //expo or linear
	  if(ftypeOfFit4Bkg==0) cout<<"*** Exponential Fit ***"<<endl;
	  if(ftypeOfFit4Bkg==1) cout<<"*** Linear Fit ***"<<endl;
	  funcbkg1->SetParNames("IntGB","MeanGB","SigmaGB","BkgInt","Slope");
	  funcbkg1->SetParameters(0.5*(totInt-intbkg1),fMass,ffactor*fSigmaSgn,intbkg1,slope1);
	}
    }
    Int_t status=fhistoInvMass->Fit(bkg1name.Data(),"R,L,E,+,0");
    if (status != 0){
      cout<<"Minuit returned "<<status<<endl;
      return kFALSE;
    }

    for(Int_t i=0;i<bkgPar;i++){
      fFitPars[bkgPar-3+i]=funcbkg1->GetParameter(i);
      //cout<<bkgPar-3+i<<"\t"<<funcbkg1->GetParameter(i);
      fFitPars[fNFinalPars+3*bkgPar-6+i]= funcbkg1->GetParError(i);
      //cout<<"\t"<<fNFinalPars+3*bkgPar-6+i<<"\t"<<funcbkg1->GetParError(i)<<endl; 
    }

    intbkg1=funcbkg1->GetParameter(3);
    if(ftypeOfFit4Bkg!=3) slope1 = funcbkg1->GetParameter(4);
    if(ftypeOfFit4Bkg==2) conc1 = funcbkg1->GetParameter(5);

  } else {
    bkgPar+=3;

    for(Int_t i=0;i<3;i++){
      fFitPars[bkgPar-3+i]=0.;
      cout<<bkgPar-3+i<<"\t"<<0.<<"\t";
      fFitPars[fNFinalPars+3*bkgPar-6+i]= 0.;
      cout<<fNFinalPars+3*bkgPar-6+i<<"\t"<<0.<<endl;
    }
  
    for(Int_t i=0;i<bkgPar-3;i++){
      fFitPars[bkgPar+i]=funcbkg->GetParameter(i);
      cout<<bkgPar+i<<"\t"<<funcbkg->GetParameter(i)<<"\t";
      fFitPars[fNFinalPars+3*bkgPar-3+i]= funcbkg->GetParError(i);
      cout<<fNFinalPars+3*bkgPar-3+i<<"\t"<< funcbkg->GetParError(i)<<endl;
    }

   
  }

  //sidebands integral - second approx (from fit)
  fSideBands = kFALSE;
  Double_t bkgInt;
  //cout<<"Compare intbkg1 = "<<intbkg1<<" and integral = ";
  if(ftypeOfFit4Sgn == 1) bkgInt=funcbkg1->Integral(fminMass,fmaxMass);
  else bkgInt=funcbkg->Integral(fminMass,fmaxMass);
  //cout<</*"------BkgInt(Fit) = "<<*/bkgInt<<endl;

  //Signal integral - first approx
  Double_t sgnInt;
  sgnInt = totInt-bkgInt;
  //cout<<"------TotInt = "<<totInt<<"\tsgnInt = "<<sgnInt<<endl;
  if (sgnInt <= 0){
    cout<<"Setting sgnInt = - sgnInt"<<endl;
    sgnInt=(-1)*sgnInt;
  }
  /*Fit All Mass distribution with exponential + gaussian (+gaussian braodened) */
  TF1 *funcmass = new TF1(massname.Data(),this,&AliHFMassFitter::FitFunction4MassDistr,fminMass,fmaxMass,fNFinalPars,"AliHFMassFitter","FitFunction4MassDistr");
  cout<<"Function name = "<<funcmass->GetName()<<endl<<endl;
  funcmass->SetLineColor(4); //blue

  //Set parameters
  cout<<"\nTOTAL FIT"<<endl;

  if(fNFinalPars==5){
    funcmass->SetParNames("TotInt","Slope","SgnInt","Mean","Sigma");
    funcmass->SetParameters(totInt,slope1,sgnInt,fMass,fSigmaSgn);

    //cout<<"Parameters set to: "<<totInt<<"\t"<<slope1<<"\t"<<sgnInt<<"\t"<<fMass<<"\t"<<fSigmaSgn<<"\t"<<endl;
    //cout<<"Limits: ("<<fminMass<<","<<fmaxMass<<")\tnPar = "<<fNFinalPars<<"\tgsidebands = "<<fSideBands<<endl;
    if(fFixPar[0]){
      funcmass->FixParameter(0,totInt);
    }
    if(fFixPar[1]){
      funcmass->FixParameter(1,slope1);
    }
    if(fFixPar[2]){
      funcmass->FixParameter(2,sgnInt);
    }
    if(fFixPar[3]){
      funcmass->FixParameter(3,fMass);
    }
    if(fFixPar[4]){
      funcmass->FixParameter(4,fSigmaSgn);
    }
  }
  if (fNFinalPars==6){
    funcmass->SetParNames("TotInt","Coef1","Coef2","SgnInt","Mean","Sigma");
    funcmass->SetParameters(totInt,slope1,conc1,sgnInt,fMass,fSigmaSgn);
 
    //cout<<"Parameters set to: "<<totInt<<"\t"<<slope1<<"\t"<<conc1<<"\t"<<sgnInt<<"\t"<<fMass<<"\t"<<fSigmaSgn<<"\t"<<endl;
    //cout<<"Limits: ("<<fminMass<<","<<fmaxMass<<")\tnPar = "<<fNFinalPars<<"\tgsidebands = "<<fSideBands<<endl;
    if(fFixPar[0])funcmass->FixParameter(0,totInt);
    if(fFixPar[1])funcmass->FixParameter(1,slope1);
    if(fFixPar[2])funcmass->FixParameter(2,conc1);
    if(fFixPar[3])funcmass->FixParameter(3,sgnInt);
    if(fFixPar[4])funcmass->FixParameter(4,fMass);
    if(fFixPar[5])funcmass->FixParameter(5,fSigmaSgn);
    //
    //funcmass->FixParameter(2,sgnInt);
  }
  if(fNFinalPars==4){
    funcmass->SetParNames("Const","SgnInt","Mean","Sigma");
    if(ftypeOfFit4Sgn == 1) funcmass->SetParameters(0.,0.5*totInt,fMass,fSigmaSgn);
    else funcmass->SetParameters(0.,totInt,fMass,fSigmaSgn);
    if(fFixPar[0]) funcmass->FixParameter(0,0.);
    if(fFixPar[1])funcmass->FixParameter(1,sgnInt);
    if(fFixPar[2])funcmass->FixParameter(2,fMass);
    if(fFixPar[3])funcmass->FixParameter(3,fSigmaSgn);
   //cout<<"Parameters set to: "<<0.5*totInt<<"\t"<<fMass<<"\t"<<fSigmaSgn<<"\t"<<endl;
    //cout<<"Limits: ("<<fminMass<<","<<fmaxMass<<")\tnPar = "<<fNFinalPars<<"\tgsidebands = "<<fSideBands<<endl;

  }

  Int_t status;

  status = fhistoInvMass->Fit(massname.Data(),"R,L,E,+,0");
  if (status != 0){
    cout<<"Minuit returned "<<status<<endl;
    return kFALSE;
  }

  cout<<"fit done"<<endl;
  //reset value of fMass and fSigmaSgn to those found from fit
  fMass=funcmass->GetParameter(fNFinalPars-2);
  fSigmaSgn=funcmass->GetParameter(fNFinalPars-1);
  
  for(Int_t i=0;i<fNFinalPars;i++){
    fFitPars[i+2*bkgPar-3]=funcmass->GetParameter(i);
    fFitPars[fNFinalPars+4*bkgPar-6+i]= funcmass->GetParError(i);
    //cout<<i+2*bkgPar-3<<"\t"<<funcmass->GetParameter(i)<<"\t\t"<<fNFinalPars+4*bkgPar-6+i<<"\t"<<funcmass->GetParError(i)<<endl;
  }
  /*
  //check: cout parameters  
  for(Int_t i=0;i<2*(fNFinalPars+2*bkgPar-3);i++){
    cout<<i<<"\t"<<fFitPars[i]<<endl;
    }
  */
  
  if(funcmass->GetParameter(fNFinalPars-1) <0 || funcmass->GetParameter(fNFinalPars-2) <0 || funcmass->GetParameter(fNFinalPars-3) <0 ) {
    cout<<"IntS or mean or sigma negative. You may tray to SetInitialGaussianSigma(..) and SetInitialGaussianMean(..)"<<endl;
    return kFALSE;
  }

  //increase counter of number of fits done
  fcounter++;

  //contour plots
  if(draw){

    for (Int_t kpar=1; kpar<fNFinalPars;kpar++){

      for(Int_t jpar=kpar+1;jpar<fNFinalPars;jpar++){
	cout<<"Par "<<kpar<<" and "<<jpar<<endl;
	
	// produce 2 contours per couple of parameters
	TGraph* cont[2] = {0x0, 0x0};
	const Double_t errDef[2] = {1., 4.}; 
	for (Int_t i=0; i<2; i++) {
	  gMinuit->SetErrorDef(errDef[i]);
	  cont[i] = (TGraph*)gMinuit->Contour(80,kpar,jpar);
	  cout<<"Minuit Status = "<<gMinuit->GetStatus()<<endl;
	}
	
	if(!cont[0] || !cont[1]){
	  cout<<"Skipping par "<<kpar<<" vs par "<<jpar<<endl;
	  continue;
	}
	  
	// set graph titles and add them to the list
	TString title = "Contour plot";
	TString titleX = funcmass->GetParName(kpar);
	TString titleY = funcmass->GetParName(jpar);
	for (Int_t i=0; i<2; i++) {
	  cont[i]->SetName( Form("cperr%d_%d%d", i, kpar, jpar) );
	  cont[i]->SetTitle(title);
	  cont[i]->GetXaxis()->SetTitle(titleX);
	  cont[i]->GetYaxis()->SetTitle(titleY);
	  cont[i]->GetYaxis()->SetLabelSize(0.033);
	  cont[i]->GetYaxis()->SetTitleSize(0.033);
	  cont[i]->GetYaxis()->SetTitleOffset(1.67);
	  
	  fContourGraph->Add(cont[i]);
	}
	
	// plot them
	TString cvname = Form("c%d%d", kpar, jpar);
	TCanvas *c4=new TCanvas(cvname,cvname,600,600);
	c4->cd();
	cont[1]->SetFillColor(38);
	cont[1]->Draw("alf");
	cont[0]->SetFillColor(9);
	cont[0]->Draw("lf");
        
      }
      
    }
    
  }

  if (ftypeOfFit4Sgn == 1) {
    delete funcbkg1;
  }
  delete funcbkg;
  delete funcmass;
  
  AddFunctionsToHisto();
  if (draw) DrawFit();
 

  return kTRUE;
}

//______________________________________________________________________________

Bool_t AliHFMassFitter::RefitWithBkgOnly(Bool_t draw){

  //perform a fit with background function only. Can be useful to try when fit fails to understand if it is because there's no signal
  //If you want to change the backgroud function or range use SetType or SetRangeFit before

  TString bkgname="funcbkgonly";
  fSideBands = kFALSE;

  TF1* funcbkg = new TF1(bkgname.Data(),this,&AliHFMassFitter::FitFunction4Bkg,fminMass,fmaxMass,fNFinalPars-3,"AliHFMassFitter","FitFunction4Bkg");

  funcbkg->SetLineColor(kBlue+3); //dark blue

  Double_t integral=fhistoInvMass->Integral(fhistoInvMass->FindBin(fminMass),fhistoInvMass->FindBin(fmaxMass),"width");

  switch (ftypeOfFit4Bkg) {
  case 0: //gaus+expo
    funcbkg->SetParNames("BkgInt","Slope"); 
    funcbkg->SetParameters(integral,-2.); 
    break;
  case 1:
    funcbkg->SetParNames("BkgInt","Slope");
    funcbkg->SetParameters(integral,-100.); 
    break;
  case 2:
    funcbkg->SetParNames("BkgInt","Coef1","Coef2");
    funcbkg->SetParameters(integral,-10.,5);
    break;
  case 3:
    cout<<"Warning! This choice does not have a lot of sense..."<<endl;
    if(ftypeOfFit4Sgn==0){
      funcbkg->SetParNames("Const");
      funcbkg->SetParameter(0,0.);
      funcbkg->FixParameter(0,0.);
    }
    break;
  default:
    cout<<"Wrong choise of ftypeOfFit4Bkg ("<<ftypeOfFit4Bkg<<")"<<endl;
    return kFALSE;
    break;
  }


  Int_t status=fhistoInvMass->Fit(bkgname.Data(),"R,L,E,+,0");
  if (status != 0){
    cout<<"Minuit returned "<<status<<endl;
    return kFALSE;
  }
  AddFunctionsToHisto();

  if(draw) DrawFit();

  return kTRUE;

}
//_________________________________________________________________________
Double_t AliHFMassFitter::GetChiSquare() const{
  TF1 *funcmass=(TF1*)fhistoInvMass->GetFunction("funcmass");
  if(!funcmass) {
    cout<<"funcmass not found"<<endl;
    return -1;
  }
  return funcmass->GetChisquare();
}

//_________________________________________________________________________
Double_t AliHFMassFitter::GetReducedChiSquare() const{
  TF1 *funcmass=(TF1*)fhistoInvMass->GetFunction("funcmass");
  if(!funcmass) {
    cout<<"funcmass not found"<<endl;
    return -1;
  }
  return funcmass->GetChisquare()/funcmass->GetNDF();
}

//*********output

//_________________________________________________________________________
void  AliHFMassFitter::GetFitPars(Float_t *vector) const {
  // Return fit parameters
  
  for(Int_t i=0;i<fParsSize;i++){
    vector[i]=fFitPars[i];
  }
}


//_________________________________________________________________________
void AliHFMassFitter::IntS(Float_t *valuewitherror) const {

  //gives the integral of signal obtained from fit parameters
  if(!valuewitherror) {
    printf("AliHFMassFitter::IntS: got a null pointer\n");
    return;
  }

  Int_t index=fParsSize/2 - 3;
  valuewitherror[0]=fFitPars[index];
  index=fParsSize - 3;
  valuewitherror[1]=fFitPars[index];
}


//_________________________________________________________________________
void AliHFMassFitter::AddFunctionsToHisto(){

  //Add the background function in the complete range to the list of functions attached to the histogram

  //cout<<"AddFunctionsToHisto called"<<endl;
  TString bkgname = "funcbkg";

  Bool_t done1=kFALSE,done2=kFALSE;

  TString bkgnamesave=bkgname;
  TString testname=bkgname;
  testname += "FullRange";
  TF1 *testfunc=(TF1*)fhistoInvMass->FindObject(testname.Data());
  if(testfunc){
    done1=kTRUE;
    testfunc=0x0;
  }
  testname="funcbkgonly";
  testfunc=(TF1*)fhistoInvMass->FindObject(testname.Data());
  if(testfunc){
    done2=kTRUE;
    testfunc=0x0;
  }

  if(done1 && done2){
    cout<<"AddFunctionsToHisto already used: exiting...."<<endl;
    return;
  }

  TList *hlist=fhistoInvMass->GetListOfFunctions();
  hlist->ls();

  if(!done2){
    TF1 *bonly=(TF1*)hlist->FindObject(testname.Data());
    if(!bonly){
      cout<<testname.Data()<<" not found looking for complete fit"<<endl;
    }else{
      bonly->SetLineColor(kBlue+3);
      hlist->Add((TF1*)bonly->Clone());
      delete bonly;
    }

  }

  if(!done1){
    TF1 *b=(TF1*)hlist->FindObject(bkgname.Data());
    if(!b){
      cout<<bkgname<<" not found, cannot produce "<<bkgname<<"FullRange and "<<bkgname<<"Recalc"<<endl;
      return;
    }

    bkgname += "FullRange";
    TF1 *bfullrange=new TF1(bkgname.Data(),this,&AliHFMassFitter::FitFunction4Bkg,fminMass,fmaxMass,fNFinalPars-3,"AliHFMassFitter","FitFunction4Bkg");
    //cout<<bfullrange->GetName()<<endl;
    for(Int_t i=0;i<fNFinalPars-3;i++){
      bfullrange->SetParName(i,b->GetParName(i));
      bfullrange->SetParameter(i,b->GetParameter(i));
      bfullrange->SetParError(i,b->GetParError(i));
    }
    bfullrange->SetLineStyle(4);
    bfullrange->SetLineColor(14);

    bkgnamesave += "Recalc";

    TF1 *blastpar=new TF1(bkgnamesave.Data(),this,&AliHFMassFitter::FitFunction4Bkg,fminMass,fmaxMass,fNFinalPars-3,"AliHFMassFitter","FitFunction4Bkg");

    TF1 *mass=fhistoInvMass->GetFunction("funcmass");

    if (!mass){
      cout<<"funcmass doesn't exist "<<endl;
      return;
    }

    //intBkg=intTot-intS
    blastpar->SetParameter(0,mass->GetParameter(0)-mass->GetParameter(fNFinalPars-3));
    blastpar->SetParError(0,mass->GetParError(fNFinalPars-3));
    if (fNFinalPars>=5) {
      blastpar->SetParameter(1,mass->GetParameter(1));
      blastpar->SetParError(1,mass->GetParError(1));
    }
    if (fNFinalPars==6) {
      blastpar->SetParameter(2,mass->GetParameter(2));
      blastpar->SetParError(2,mass->GetParError(2));
    }

    blastpar->SetLineStyle(1);
    blastpar->SetLineColor(2);

    hlist->Add((TF1*)bfullrange->Clone());
    hlist->Add((TF1*)blastpar->Clone());
    hlist->ls();
  
    delete bfullrange;
    delete blastpar;
    
  }


}

//_________________________________________________________________________

TH1F* AliHFMassFitter::GetHistoClone() const{

  TH1F* hout=(TH1F*)fhistoInvMass->Clone(fhistoInvMass->GetName());
  return hout;
}
//_________________________________________________________________________

void AliHFMassFitter::WriteHisto(TString path) const {

  //Write the histogram in the default file HFMassFitterOutput.root

  if (fcounter == 0) {
    cout<<"Use MassFitter method before WriteHisto"<<endl;
    return;
  }
  TH1F* hget=(TH1F*)fhistoInvMass->Clone();

  path += "HFMassFitterOutput.root";
  TFile *output;
 
  if (fcounter == 1) output = new TFile(path.Data(),"recreate");
  else output = new TFile(path.Data(),"update");
  output->cd();
  hget->Write();
  fContourGraph->Write();


  output->Close();

  cout<<fcounter<<" "<<hget->GetName()<<" written in "<<path<<endl;

  delete output;
  
}

//_________________________________________________________________________

void AliHFMassFitter::WriteNtuple(TString path) const{
  //TNtuple* nget=(TNtuple*)fntuParam->Clone();
  path += "HFMassFitterOutput.root";
  TFile *output = new TFile(path.Data(),"update");
  output->cd();
  fntuParam->Write();
  //nget->Write();
  output->Close();
  //cout<<nget->GetName()<<" written in "<<path<<endl;
  cout<<fntuParam->GetName()<<" written in "<<path<<endl;
  /*
  if(nget) {
    //delete nget;
    nget=NULL;
  }
  */

  delete output;
}

//_________________________________________________________________________
void AliHFMassFitter::WriteCanvas(TString userIDstring,TString path,Double_t nsigma,Int_t writeFitInfo,Bool_t draw) const{

 //write the canvas in a root file

  gStyle->SetOptStat(0);
  gStyle->SetCanvasColor(0);
  gStyle->SetFrameFillColor(0);

  TString type="";

  switch (ftypeOfFit4Bkg){
  case 0:
    type="Exp"; //3+2
    break;
  case 1:
    type="Lin"; //3+2
    break;
  case 2:
    type="Pl2"; //3+3
    break;
  case 3:
    type="noB"; //3+1
    break;
  }

  TString filename=Form("%sMassFit.root",type.Data());
  filename.Prepend(userIDstring);
  path.Append(filename);

  TFile* outputcv=new TFile(path.Data(),"update");

  TCanvas* c=(TCanvas*)GetPad(nsigma,writeFitInfo);
  c->SetName(Form("%s%s%s",c->GetName(),userIDstring.Data(),type.Data()));
  if(draw)c->DrawClone();
  outputcv->cd();
  c->Write();
  outputcv->Close();
}

//_________________________________________________________________________

TVirtualPad* AliHFMassFitter::GetPad(Double_t nsigma,Int_t writeFitInfo)const{
  //return a TVirtualPad with the fitted histograms and info

  TString cvtitle="fit of ";
  cvtitle+=fhistoInvMass->GetName();
  TString cvname="c";
  cvname+=fcounter;

  TCanvas *c=new TCanvas(cvname,cvtitle);
  PlotFit(c->cd(),nsigma,writeFitInfo);
  return c->cd();
}
//_________________________________________________________________________

void AliHFMassFitter::PlotFit(TVirtualPad* pd,Double_t nsigma,Int_t writeFitInfo)const{
  //plot histogram, fit functions and write parameters according to verbosity level (0,1,>1)
  gStyle->SetOptStat(0);
  gStyle->SetCanvasColor(0);
  gStyle->SetFrameFillColor(0);

  cout<<"nsigma = "<<nsigma<<endl;
  cout<<"Verbosity = "<<writeFitInfo<<endl;

  TH1F* hdraw=GetHistoClone();
  
  if(!hdraw->GetFunction("funcmass") && !hdraw->GetFunction("funcbkgFullRange") && !hdraw->GetFunction("funcbkgRecalc")&& !hdraw->GetFunction("funcbkgonly")){
    cout<<"Probably fit failed and you didn't try to refit with background only, there's no function to be drawn"<<endl;
    return;
  }
 
  if(hdraw->GetFunction("funcbkgonly")){ //Warning! if this function is present, no chance to draw the other!
    cout<<"Drawing background fit only"<<endl;
    hdraw->SetMinimum(0);
    hdraw->GetXaxis()->SetRangeUser(fminMass,fmaxMass);
    pd->cd();
    hdraw->SetMarkerStyle(20);
    hdraw->DrawClone("PE");
    hdraw->GetFunction("funcbkgonly")->DrawClone("sames");

    if(writeFitInfo > 0){
      TPaveText *pinfo=new TPaveText(0.6,0.86,1.,1.,"NDC");     
      pinfo->SetBorderSize(0);
      pinfo->SetFillStyle(0);
      TF1* f=hdraw->GetFunction("funcbkgonly");
      for (Int_t i=0;i<fNFinalPars-3;i++){
	pinfo->SetTextColor(kBlue+3);
	TString str=Form("%s = %f #pm %f",f->GetParName(i),f->GetParameter(i),f->GetParError(i));
	pinfo->AddText(str);
      }

      pinfo->AddText(Form("Reduced #chi^{2} = %.3f",f->GetChisquare()/f->GetNDF()));
      pd->cd();
      pinfo->DrawClone();

 
    }

    return;
  }
  
  hdraw->SetMinimum(0);
  hdraw->GetXaxis()->SetRangeUser(fminMass,fmaxMass);
  pd->cd();
  hdraw->SetMarkerStyle(20);
  hdraw->DrawClone("PE");
//   if(hdraw->GetFunction("funcbkgFullRange")) hdraw->GetFunction("funcbkgFullRange")->DrawClone("same");
//   if(hdraw->GetFunction("funcbkgRecalc")) hdraw->GetFunction("funcbkgRecalc")->DrawClone("same");
  if(hdraw->GetFunction("funcmass")) hdraw->GetFunction("funcmass")->DrawClone("same");

  if(writeFitInfo > 0){
    TPaveText *pinfob=new TPaveText(0.6,0.86,1.,1.,"NDC");
    TPaveText *pinfom=new TPaveText(0.6,0.7,1.,.87,"NDC");
    pinfob->SetBorderSize(0);
    pinfob->SetFillStyle(0);
    pinfom->SetBorderSize(0);
    pinfom->SetFillStyle(0);
    TF1* ff=fhistoInvMass->GetFunction("funcmass");

    for (Int_t i=fNFinalPars-3;i<fNFinalPars;i++){
      pinfom->SetTextColor(kBlue);
      TString str=Form("%s = %f #pm %f",ff->GetParName(i),ff->GetParameter(i),ff->GetParError(i));
      if(!(writeFitInfo==1 && i==fNFinalPars-3)) pinfom->AddText(str);
    }
    pd->cd();
    pinfom->DrawClone();

    TPaveText *pinfo2=new TPaveText(0.1,0.1,0.6,0.4,"NDC");
    pinfo2->SetBorderSize(0);
    pinfo2->SetFillStyle(0);

    Double_t signif, signal, bkg, errsignif, errsignal, errbkg;

    Significance(nsigma,signif,errsignif);
    Signal(nsigma,signal,errsignal);
    Background(nsigma,bkg, errbkg);
    /* 
      Significance(1.828,1.892,signif,errsignif);
      Signal(1.828,1.892,signal,errsignal);
      Background(1.828,1.892,bkg, errbkg);
    */
    TString str=Form("Significance (%.0f#sigma) %.1f #pm %.1f ",nsigma,signif,errsignif);
    pinfo2->AddText(str);
    str=Form("S (%.0f#sigma) %.0f #pm %.0f ",nsigma,signal,errsignal);
    pinfo2->AddText(str);
    str=Form("B (%.0f#sigma) %.0f #pm %.0f",nsigma,bkg,errbkg);
    pinfo2->AddText(str);

    pd->cd();
    pinfo2->Draw();

    if(writeFitInfo > 1){
      for (Int_t i=0;i<fNFinalPars-3;i++){
	pinfob->SetTextColor(kRed);
	str=Form("%s = %f #pm %f",ff->GetParName(i),ff->GetParameter(i),ff->GetParError(i));
	pinfob->AddText(str);
      }
      pd->cd();
      pinfob->DrawClone();
    }


  }
  return;
}

//_________________________________________________________________________

void AliHFMassFitter::DrawHere(TVirtualPad* pd,Double_t nsigma,Int_t writeFitInfo) const {
  //draws histogram together with fit functions with default nice colors in user canvas
  PlotFit(pd,nsigma,writeFitInfo);

  pd->Draw();
 
}
//_________________________________________________________________________
void AliHFMassFitter::DrawFit(Double_t nsigma) const{

  //draws histogram together with fit functions with default nice colors
  gStyle->SetOptStat(0);
  gStyle->SetCanvasColor(0);
  gStyle->SetFrameFillColor(0);


  TCanvas* c=(TCanvas*)GetPad(nsigma,1);
  c->Draw();
  
}


//_________________________________________________________________________

void AliHFMassFitter::PrintParTitles() const{

  //prints to screen the parameters names

  TF1 *f=fhistoInvMass->GetFunction("funcmass");
  if(!f) {
    cout<<"Fit function not found"<<endl;
    return;
  }

  cout<<"Parameter Titles \n";
  for(Int_t i=0;i<fNFinalPars;i++){
    cout<<"Par "<<i<<": "<<f->GetParName(i)<<endl;
  }
  cout<<endl;

}

//************ significance

//_________________________________________________________________________

void AliHFMassFitter::Signal(Double_t nOfSigma,Double_t &signal,Double_t &errsignal) const {
  // Return signal integral in mean+- n sigma

  if(fcounter==0) {
    cout<<"Use MassFitter method before Signal"<<endl;
    return;
  }

  Double_t min=fMass-nOfSigma*fSigmaSgn;
  Double_t max=fMass+nOfSigma*fSigmaSgn;

  Signal(min,max,signal,errsignal);


  return;

}

//_________________________________________________________________________

void AliHFMassFitter::Signal(Double_t min, Double_t max, Double_t &signal,Double_t &errsignal) const {

  // Return signal integral in a range
  
  if(fcounter==0) {
    cout<<"Use MassFitter method before Signal"<<endl;
    return;
  }

  //functions names
  TString bkgname="funcbkgRecalc";
  TString bkg1name="funcbkg1Recalc";
  TString massname="funcmass";


  TF1 *funcbkg=0;
  TF1 *funcmass=fhistoInvMass->GetFunction(massname.Data());
  if(!funcmass){
    cout<<"AliHFMassFitter::Signal() ERROR -> Mass distr function not found!"<<endl;
    return;
  }

  if(ftypeOfFit4Sgn == 0) funcbkg=fhistoInvMass->GetFunction(bkgname.Data());
  else funcbkg=fhistoInvMass->GetFunction(bkg1name.Data());

  if(!funcbkg){
    cout<<"AliHFMassFitter::Signal() ERROR -> Bkg function not found!"<<endl;
    return;
  }

  Int_t np=fNFinalPars-3;

  Double_t intS,intSerr;

 //relative error evaluation
  intS=funcmass->GetParameter(np);
  intSerr=funcmass->GetParError(np);

  cout<<"Sgn relative error evaluation from fit: "<<intSerr/intS<<endl;
  Double_t background,errbackground;
  Background(min,max,background,errbackground);

  //signal +/- error in the range

  Double_t mass=funcmass->Integral(min, max)/fhistoInvMass->GetBinWidth(4);
  signal=mass - background;
  errsignal=(intSerr/intS)*signal;/*assume relative error is the same as for total integral*/

}

//_________________________________________________________________________

void AliHFMassFitter::Background(Double_t nOfSigma,Double_t &background,Double_t &errbackground) const {
  // Return background integral in mean+- n sigma

  if(fcounter==0) {
    cout<<"Use MassFitter method before Background"<<endl;
    return;
  }
  Double_t min=fMass-nOfSigma*fSigmaSgn;
  Double_t max=fMass+nOfSigma*fSigmaSgn;

  Background(min,max,background,errbackground);

  return;
  
}
//___________________________________________________________________________

void AliHFMassFitter::Background(Double_t min, Double_t max, Double_t &background,Double_t &errbackground) const {
  // Return background integral in a range

  if(fcounter==0) {
    cout<<"Use MassFitter method before Background"<<endl;
    return;
  }

  //functions names
  TString bkgname="funcbkgRecalc";
  TString bkg1name="funcbkg1Recalc";

  TF1 *funcbkg=0;
  if(ftypeOfFit4Sgn == 0) funcbkg=fhistoInvMass->GetFunction(bkgname.Data());
  else funcbkg=fhistoInvMass->GetFunction(bkg1name.Data());
  if(!funcbkg){
    cout<<"AliHFMassFitter::Background() ERROR -> Bkg function not found!"<<endl;
    return;
  }


  Double_t intB,intBerr;

  //relative error evaluation: from final parameters of the fit
  if(ftypeOfFit4Bkg==3 && ftypeOfFit4Sgn == 0) cout<<"No background fit: Bkg relative error evaluation put to zero"<<endl;
  else{
    intB=funcbkg->GetParameter(0);
    intBerr=funcbkg->GetParError(0);
    cout<<"Bkg relative error evaluation: from final parameters of the fit: "<<intBerr/intB<<endl;
  }

  //relative error evaluation: from histo
   
  intB=fhistoInvMass->Integral(1,fSideBandl)+fhistoInvMass->Integral(fSideBandr,fNbin);
  Double_t sum2=0;
  for(Int_t i=1;i<=fSideBandl;i++){
    sum2+=fhistoInvMass->GetBinError(i)*fhistoInvMass->GetBinError(i);
  }
  for(Int_t i=fSideBandr;i<=fNbin;i++){
    sum2+=fhistoInvMass->GetBinError(i)*fhistoInvMass->GetBinError(i);
  }

  intBerr=TMath::Sqrt(sum2);
  cout<<"Bkg relative error evaluation: from histo: "<<intBerr/intB<<endl;
  
  cout<<"Last estimation of bkg error is used"<<endl;

  //backround +/- error in the range
  if (ftypeOfFit4Bkg == 3 && ftypeOfFit4Sgn == 0) {
    background = 0;
    errbackground = 0;
  }
  else{
    background=funcbkg->Integral(min,max)/(Double_t)fhistoInvMass->GetBinWidth(2);
    errbackground=intBerr/intB*background; // assume relative error is the same as for total integral
    //cout<<"integral = "<<funcbkg->Integral(min, max)<<"\tbinW = "<<fhistoInvMass->GetBinWidth(2)<<endl;
  }
  return;

}


//__________________________________________________________________________

void AliHFMassFitter::Significance(Double_t nOfSigma,Double_t &significance,Double_t &errsignificance) const  {
  // Return significance in mean+- n sigma
 
  Double_t min=fMass-nOfSigma*fSigmaSgn;
  Double_t max=fMass+nOfSigma*fSigmaSgn;
  Significance(min, max, significance, errsignificance);

  return;
}

//__________________________________________________________________________

void AliHFMassFitter::Significance(Double_t min, Double_t max, Double_t &significance,Double_t &errsignificance) const {
  // Return significance integral in a range

  Double_t signal,errsignal,background,errbackground;
  Signal(min, max,signal,errsignal);
  Background(min, max,background,errbackground);

  if (signal+background <= 0.){
    cout<<"Cannot calculate significance because of div by 0!"<<endl;
    significance=-1;
    errsignificance=0;
    return;
  }

  significance =  signal/TMath::Sqrt(signal+background);

  errsignificance = TMath::Sqrt(significance*significance/(signal+background)/(signal+background)*(1/4.*errsignal*errsignal+errbackground*errbackground)+significance*significance/signal/signal*errsignal*errsignal);
  
  return;
}