void gauexp(){
  gStyle->SetFuncWidth(1);

  f=new TF1("f","1.0048*exp( -0.0000015496*x )",0.,10000.);
  f->SetTitle("Exponetial versus Gaussian Extrapolation Correction");
  f->SetLineColor(2);
  f->SetLineStyle(2);
  f->SetMinimum(0.98);
  g=new TF1("g","1.0024*exp( -(x**2/2./(51111.**2)) )",0.,10000.);
  g->SetTitle("Gaussian fit to data");
  g->SetLineColor(3);
  g->SetLineStyle(3);    
  fg=new TF1("fg","0.5*1.0048*exp( -0.0000015496*x )+0.5*1.0024*exp( -(x**2/2./(51111.**2)) )",0.,10000.);
  g->SetTitle("half exponential half gaussian in data");
  g->SetLineColor(4);
  g->SetLineStyle(4);      
  f2=new TF1("f2","1.0106*exp( -0.0000015496*x )",0.,10000.);
  f2->SetTitle("exponential in simulation");
  f2->SetLineColor(6);
  f2->SetLineStyle(6);    
  g2=new TF1("g2","1.0106*exp( -(x**2/2./(51111.**2)) )",0.,10000.);
  g2->SetTitle("Gaussian in simulation");
  g2->SetLineColor(7);
  g2->SetLineStyle(7);    
  fg2=new TF1("fg2","0.5*1.0106*(exp( -0.0000015496*x )+exp( -(x**2/2./(51111.**2)) ))",0.,10000.);
  fg2->SetTitle("half exponential half Gaussian in simulation");
  fg2->SetLineColor(8);
  fg2->SetLineStyle(8);

  f->Draw();
  g->Draw("same");
  fg->Draw("same");
  f2->Draw("same");
  g2->Draw("same");
  fg2->Draw("same");

  fmut=new TF1("fmut","1./1325.77864*exp(-x/2197.03)",0.,10000.);



  ft=new TF1("f","1.0048*exp( -0.0000015496*x )*1./1325.77864*exp(-x/2197.03)",0.,10000.);
  ft->SetTitle("Exponetial versus Gaussian Extrapolation Correction");
  ft->SetLineColor(2);
  ft->SetLineStyle(2);
  ft->SetMinimum(0.98);
  gt=new TF1("g","1.0024*exp( -(x**2/2./(51111.**2)) )*1./1325.77864*exp(-x/2197.03)",0.,10000.);
  gt->SetTitle("Gaussian fit to data");
  gt->SetLineColor(3);
  gt->SetLineStyle(3);    
  fgt=new TF1("fg","0.5*(1.0048*exp( -0.0000015496*x )+1.0024*exp( -(x**2/2./(51111.**2)) ))*1./1325.77864*exp(-x/2197.03)",0.,10000.);
  gt->SetTitle("half exponential half gaussian in data");
  gt->SetLineColor(4);
  gt->SetLineStyle(4);      
  ft2=new TF1("f2","1.0106*exp( -0.0000015496*x )*1./1325.77864*exp(-x/2197.03)",0.,10000.);
  ft2->SetTitle("exponential in simulation");
  ft2->SetLineColor(6);
  ft2->SetLineStyle(6);    
  gt2=new TF1("g2","1.0106*exp( -(x**2/2./(51111.**2)) )*1./1325.77864*exp(-x/2197.03)",0.,10000.);
  gt2->SetTitle("Gaussian in simulation");
  gt2->SetLineColor(7);
  gt2->SetLineStyle(7);    
  fgt2=new TF1("fg2","0.5*1.0106*(exp( -0.0000015496*x )+exp( -(x**2/2./(51111.**2)) ))*1./1325.77864*exp(-x/2197.03)",0.,10000.);
  fgt2->SetTitle("half exponential half Gaussian in simulation");
  fgt2->SetLineColor(8);
  fgt2->SetLineStyle(8);
  
  printf("Data, exponential  Pmu(0)=%8.6f  <Pmu>=%8.6f \n",f->Eval(0.),ft->Integral(1050.,9000.));
  printf("Data, Gaussian     Pmu(0)=%8.6f  <Pmu>=%8.6f \n",g->Eval(0.),gt->Integral(1050.,9000.));
  printf("Data, exp+Gaus     Pmu(0)=%8.6f  <Pmu>=%8.6f \n",fg->Eval(0.),fgt->Integral(1050.,9000.));
  printf("Sim,  exponential  Pmu(0)=%8.6f  <Pmu>=%8.6f \n",f2->Eval(0.),ft2->Integral(1050.,9000.));
  printf("Sim,  Gaussian     Pmu(0)=%8.6f  <Pmu>=%8.6f \n",g2->Eval(0.),gt2->Integral(1050.,9000.));
  printf("Sim,  exp+Gaus     Pmu(0)=%8.6f  <Pmu>=%8.6f \n",fg2->Eval(0.),fgt2->Integral(1050.,9000.));
  

}