void ovplot() {

string line, lineold, lineold2;
string det[15];
string olaps ("Overlaps");
string str3;
char *str3c;
char *htitle ("dummy");
int pos1, pos2, ndet, len;
float val, mean;

 ifstream infile;
 infile.open ("stats.txt");

if (infile.is_open())  {
  int nbins=200, low=0.0, hi=25;
  TH1F *h0 = new TH1F("h0", "All overflows (cm)",nbins,low,hi); 
  TH1F *h1 = new TH1F("h1", "ZDC overflows (cm)",nbins,low,hi); 
  TH1F *h2 = new TH1F("h2", "FCL overflows (cm)",nbins,low,hi); 
  TH1F *h3 = new TH1F("h3", "ITR overflows (cm)",nbins,low,hi); 
  TH1F *h4 = new TH1F("h4", "CRK overflows (cm)",nbins,low,hi); 
  TH1F *h5 = new TH1F("h5", "PAD overflows (cm)",nbins,low,hi); 
  TH1F *h6 = new TH1F("h6", "TOF overflows (cm)",nbins,low,hi); 
  TH1F *h7 = new TH1F("h7", "EMC overflows (cm)",nbins,low,hi); 
  TH1F *h8 = new TH1F("h8", "HBD overflows (cm)",nbins,low,hi); 
  TH1F *h9 = new TH1F("h9", "MUM overflows (cm)",nbins,low,hi); 
  TH1F *h10= new TH1F("h10","MUI overflows (cm)",nbins,low,hi); 
  TH1F *h11= new TH1F("h11","MUPC overflows (cm)",nbins,low,hi); 

  while (! infile.eof() ) {
    getline (infile,line);
    lineold2 = lineold;              // save 2 lines back, has the detector name
    lineold = line;
    pos1 = line.find("Overlaps");    // position of "Overlaps" in str
    if ( pos1>1 ){                   // New detector
      ndet++;                        //
      sprintf(htitle,"hist%d",ndet);
      cout <<htitle<<"  "<<lineold2<<endl;
      det[ndet] = lineold2;          // save detector name
    }

    pos2 = line.find("ovlp=");       // position of start of "ovlp=" in str
    if ( pos2>1 ){
      len = line.length();
      str3 = line.substr (pos2+5);   // get from "=" to the end, = distance in cm
      str3c = &str3[0];              // convert string to char
      sscanf(str3c, "%f", &val);     // convert char to float
      
      switch (ndet) {
        case 1:  h1->Fill(val);  h0->Fill(val); break;
        case 2:  h2->Fill(val);  h0->Fill(val); break;
        case 3:  h3->Fill(val);  h0->Fill(val); break;
        case 4:  h4->Fill(val);  h0->Fill(val); break;
        case 5:  h5->Fill(val);  h0->Fill(val); break;
        case 6:  h6->Fill(val);  h0->Fill(val); break;
        case 7:  h7->Fill(val);  h0->Fill(val); break;
        case 8:  h8->Fill(val);  h0->Fill(val); break;
        case 9:  h9->Fill(val);  h0->Fill(val); break;
        case 10: h10->Fill(val); h0->Fill(val); break;
        case 11: h11->Fill(val); h0->Fill(val); break;
      }   // end switch
    }     // end line with "ovlp="
  }       // loop over all lines
}         // input file OK


infile.close();
c1->SetLogy();

h1->SetLineColor(1);
h2->SetLineColor(3);
h3->SetLineColor(2);
h4->SetLineColor(4);
h5->SetLineColor(5);
h6->SetLineColor(6);
h7->SetLineColor(7);
h8->SetLineColor(8);
h9->SetLineColor(9);
h10->SetLineColor(10);
h11->SetLineColor(11);

h3->Draw();        // biggest one first

h1->Draw("same");
h2->Draw("same");

h4->Draw("same");
h5->Draw("same");
h6->Draw("same");
h7->Draw("same");
h8->Draw("same");
h9->Draw("same");
h10->Draw("same");
h11->Draw("same");

h0->SetLineColor(1);
h0->SetLineStyle(2);   // 2 = dashed
h0->Draw("same");

                       // print out the means:
float mean = h1->GetMean();  cout<< det[1]  <<" : "<<mean<<endl;
float mean = h2->GetMean();  cout<< det[2 ] <<" : "<<mean<<endl;
float mean = h3->GetMean();  cout<< det[3 ] <<" : "<<mean<<endl;
float mean = h4->GetMean();  cout<< det[4 ] <<" : "<<mean<<endl;
float mean = h5->GetMean();  cout<< det[5 ] <<" : "<<mean<<endl;
float mean = h6->GetMean();  cout<< det[6 ] <<" : "<<mean<<endl;
float mean = h7->GetMean();  cout<< det[7 ] <<" : "<<mean<<endl;
float mean = h8->GetMean();  cout<< det[8 ] <<" : "<<mean<<endl;
float mean = h9->GetMean();  cout<< det[9 ] <<" : "<<mean<<endl;
float mean = h10->GetMean(); cout<< det[10] <<" : "<<mean<<endl;
float mean = h11->GetMean(); cout<< det[11] <<" : "<<mean<<endl;

float mean = h0->GetMean(); cout<< All <<" : "<<mean<<endl;


}