void viewmpv(int counter){


  char hodofile[128];
  sprintf(hodofile, "hodoMPV.dat");
  ifstream INF1(hodofile);

  double X[500];
  double Y[500][500];
  
  int cnt = 0;
  while (!INF1.eof()){

    string str1;
    getline(INF1,str1);
    stringstream ss(str1);

    ss>>X[cnt];
    int c1=0;
    while (ss){
      ss>>Y[c1++][cnt];
    }
    cnt++;
  }
  cnt -=1;
  INF1.close();

  while (counter>0){

    TGraphErrors *gr = new TGraphErrors(cnt,X,Y[counter],NULL,NULL);
    gr->SetMarkerStyle(21);
    gr->SetMarkerColor(2);
    gr->Draw("AP");
    char tit[128];
    sprintf(tit,"Hodoscope Coutnter # %d",counter);
    gr->SetTitle(tit);
    gr->GetXaxis()->SetTitle("Run Number #");
    gr->GetYaxis()->SetTitle("MPV ADC counts");
    double max = TMath::MaxElement(cnt,gr->GetY());
    gr->GetYaxis()->SetRangeUser(0.,max*1.1);
    gPad->SetGrid();
    gPad->Update();
    cout<<"another ocunter#? (-1 exit) ";
    cin>>counter;
  }
  
  



}