//   MXL  10/03/2019  
//
//   DP detectorID == 55,56,57,58; and 59, 60,61,62
//
//   if(hit->get_detector_id() >= 55 and hit->get_detector_id() <=62) {
//   if(parID_nhits_dp.find(track_id)!=parID_nhits_dp.end())
//      parID_nhits_dp[track_id] = parID_nhits_dp[track_id]+1;
//    else
//    parID_nhits_dp[track_id] = 1;
//
//
{

  gROOT->Reset();
  
  //  gROOT->SetStyle("Plain");
  //  gStyle->SetOptStat("Plain");
  //  gStyle->SetPadLeftMargin(0.15);
  // gStyle->SetPadBottomMargin(0.2);
  //  gStyle->SetLineWidth(1.5);


  //  TCanvas * c1 = new TCanvas("c1","Truth",10,20,1000,1000);
  c1 = new TCanvas("c1","Truth Tracks",10,20,1000,1000);
  c2 = new TCanvas("c2","Reco'd single-muons",100,200,1000,800);
  c3 = new TCanvas("c3","Reco'd di-muons",200,300,1000,1000);

  c4 = new TCanvas("c4","Reco'd single-muon cuts",300,400,800,800);


  //  TCut XX1 = "dimu_mass<10";   // reconstructed dimuons
  XX1 = "dimu_mass<10 && dimu_mass > 0.5";   // reconstructed dimuons
  XX2 = "detectorID>54 && detectorID<63";   //DP has hits  

  //-- reco'd track
  //  XX3 = "n_tracks>0&&gy_st1<1000&&gndp>1&&gpz_st1>20 && abs(gpy_st1)>2.0 && rec_id<1000";
  XX3 = "n_tracks>0&&gy_st1<1000&&gndp>1&&gpz_st1>20 && abs(gpy_st1)>1.0 && rec_id<1000";

  // -- define variables

  const char* reco_vz = "613 - gy_st1/gpy_st1*sqrt(gpx_st1**2 + gpy_st1**2 + gpz_st1**2)"; 

  
  //--- global ---
  c1->Divide(4,3);

  c1->cd(1)->SetLogy();
  Truth->Draw("n_tracks");

  c1->cd(2)->SetLogy();
  Truth->Draw("detectorID"); // -- detectorID[74 = max # of hits]

  c1->cd(3)->SetLogy();
  Truth->Draw("detectorZ"); // -- detectorZ[74]

  c1->cd(4)->SetLogy();
  Truth->Draw("nHits");  // 

  c1->cd(5);
  Truth->Draw("pid[0]");

  c1->cd(6);
  Truth->Draw("pid[1]");


  c1->cd(7)->SetLogy();
  Truth->Draw("gvz[0]");
  Truth->Draw("vz[0]","","same");


  c1->cd(8);
  Truth->Draw("gndp[0]");

  c1->cd(9)->SetLogy();
  Truth->Draw("dimu_gmass[0]");
  Truth->Draw("dimu_mass[0]","","same");

  c1->cd(10)->SetLogy();
  //  Truth->Draw("dimu_gmass[0]");
  Truth->Draw("dimu_mass[0]","dimu_mass[0]<100");


  c1->cd(11)->SetLogy();
  Truth->Draw("gndimu");

  c1->cd(12)->SetLogy();
  Truth->Draw("dimu_gpz[0]");





  //-- Reco'd single muons & DP detectors ----

   c2->Divide(3,2);

   c2->cd(1);
   Truth->Draw(reco_vz,XX3);  // at least one reco's muon

   c2->cd(2);
   Truth->Draw("pz_st1[0]", XX3);   // -- pz_st1[4]

   c2->cd(3);
   Truth->Draw("pz_st1[1]", XX3);   // -- pz_st1[4]

   c2->cd(4);
   Truth->Draw("gpz", XX3);  // -- gpz[4]

   c2->cd(5);
   Truth->Draw("pz_st1-gpz", XX3);

   c2->cd(6);
   Truth->Draw("gndp", XX3);  // -- gndp[4]


  //-- Reco'd dimuons & DP detectors ----

   c3->Divide(3,3);

  c3->cd(1);
  Truth->Draw("dimu_mass",XX1);  // dimu_mass < 10

  c3->cd(2);
  Truth->Draw("gndp[0]",XX1);

  c3->cd(3);
  Truth->Draw("gpz[0]",XX1);
  Truth->Draw("pz[0]",XX1,"same");


  c3->cd(4);
  Truth->Draw("gpz[0]:pz[0]", XX1);

  c3->cd(5);
  Truth->Draw("vx[0]:vy[0]",XX1);

  c3->cd(6);
  Truth->Draw("vx[0]:vx[1]",XX1);

  c3->cd(7);
  Truth->Draw("detectorID",XX1);

  c3->cd(8);
  Truth->Draw("detectorZ",XX1);


  c3->cd(9);
  Truth->Draw("eventID",XX1);

  // -- single muon cuts --- 
  //  XX3 = "n_tracks>0&&gy_st1<1000&&gndp>1&&gpz_st1>20 && abs(gpy_st1)>2.0 && rec_id<1000";

  c4->cd()->Divide(3,2);

  c4->cd(1);
  Truth->Draw("n_tracks",XX3);

  c4->cd(2);
  Truth->Draw("gy_st1",XX3) ;

  c4->cd(3);
  Truth->Draw("gndp",XX3);

  c4->cd(4);
  Truth->Draw("gpz_st1", XX3);

  c4->cd(5);
  Truth->Draw("gpy_st1", XX3);

  c4->cd(6);
  Truth->Draw("rec_id", XX3);

}