void PlotInverse () {

  Int_t n = 4;
  Double_t R[] = {300,500,700,900} ;
  Double_t sigma_e[] = {327,45,9.5,2.7} ;
  Double_t sigma_m[] = {306,43,9.1,2.7} ;
  Double_t sigma_em[] = {623,87,18.9,5.4} ;
  Double_t sigma_t[4] ;

  for (Int_t n=0; n<=3; n++){
    
    sigma_t[n]=TMath::Log10(sigma_e[n]+sigma_m[n]+sigma_em[n]);
    sigma_e[n]=TMath::Log10(sigma_e[n]);
    sigma_m[n]=TMath::Log10(sigma_m[n]);
    sigma_em[n]=TMath::Log10(sigma_em[n]);

  }


  TGraph* gr_e = new TGraph (n,sigma_e,R);
  TGraph* gr_m = new TGraph (n,sigma_m,R);
  TGraph* gr_em = new TGraph (n,sigma_em,R);
  TGraph* gr_t = new TGraph (n,sigma_t,R);

  TCanvas* c1 = new TCanvas ("c1","c1");

  gr_m->SetLineColor(4);
  gr_m->SetLineWidth(3);
  gr_m->SetMarkerStyle(8);
  gr_m->SetMarkerSize(1.5);
  gr_m->SetMarkerColor(4);
  gr_m->Draw("AP");
  gr_m->GetYaxis()->SetRangeUser(250,950);
  gr_m->GetXaxis()->SetRangeUser(0.1,4);
  gr_t->SetLineColor(1);
  gr_t->SetLineWidth(3);
  gr_t->SetMarkerStyle(4);
  gr_t->SetMarkerSize(1.5);
  gr_t->SetMarkerColor(1);
  gr_t->Draw("P");
//   gr_t->GetYaxis()->SetRangeUser(250,950);
//   gr_t->GetXaxis()->SetRangeUser(0.1,4);
  gr_m->GetYaxis()->SetTitle("R^{-1} (GeV)");
  gr_m->GetXaxis()->SetTitle("Log_{10}#sigma#timesB.R.#timesA (fb)"); 
  gr_em->SetLineColor(8);
  gr_em->SetLineWidth(3);
  gr_em->SetMarkerColor(8);
  gr_em->SetMarkerStyle(22);
  gr_em->SetMarkerSize(1.5);
  gr_em->Draw("P");
  gr_e->SetLineColor(2);
  gr_e->SetLineWidth(3);
  gr_e->SetMarkerStyle(21);
  gr_e->SetMarkerSize(1.5);
  gr_e->SetMarkerColor(2);
  gr_e->Draw("P");

  TLegend* leg = new TLegend (0.6,0.6,0.89,0.89);
  leg->AddEntry(gr_e,"4e","lp");
  leg->AddEntry(gr_m,"4#mu","lp");
  leg->AddEntry(gr_em,"2e2#mu","lp");
  leg->AddEntry(gr_t,"total","lp");
  leg->Draw();

  TSpline3 *s3=new TSpline3("s3",gr_e);
  s3->SetLineColor(1);
  s3->SetLineStyle(2);
  s3->Draw("l same");
   

}