{
TFile f("file.root");
    TF1 *f1 = new TF1("f1","10.-x",0,10);
    f1->SetParameter(0,1);
   
    
    TF1 *f2 = new TF1("f2","gaus(x)",0,10);
    f2->SetParameter(0,2);
    f2->SetParameter(1,4);
    f2->SetParameter(2,2.5);
    
   
    TF1 *f3 = new TF1("f3","[0]*TMath::Exp( -0.5* ((x-[1])/[2])*((x-[1])/[2]) ) + [4]*10. - [5]*x",0,10);
    //f3->Draw();
    f3->SetParameter(0,2);
    f3->SetParameter(2,2.5);
    f3->SetParameter(1,4);
  cout<<h->Integral()<<endl;
  h->Fit(f3); 


}