void calc_6g_yields(){
  double eta_6g[45],deta_6g[45];
  double etap_6g[45],detap_6g[45];
  for (unsigned int i=1;i<46;i++){
    unsigned int k=i-1;
    double yield[2];
    double unc[2];
    calc_6g_yield(i,yield,unc); 
    eta_6g[k]=yield[0];
    deta_6g[k]=unc[0];
    etap_6g[k]=yield[1];
    detap_6g[k]=unc[1];
  }
  ofstream fout2("eta_6g_yields.dat");
  for (int j=0;j<45;j++){
    fout2 << 2.9+0.2*j << " " << eta_6g[j] << " " << deta_6g[j] << " " << etap_6g[j] << " "
	  << detap_6g[j] << endl;
  }
  fout2.close();

  double egamma[45];
  for (int j=0;j<45;j++) egamma[j]=2.9+0.2*j;
  TGraphErrors *g1=new TGraphErrors(45,egamma,eta_6g,0,deta_6g);
  g1->Draw();
  TGraphErrors *g2=new TGraphErrors(45,egamma,etap_6g,0,detap_6g);
  g2->Draw("same");



  
 }