Timewalk plots are made and fitted for one pixel

Time walk correction/onepixel_tree.C

+void timewalkfit(TGraphErrors* graph){
+
+  auto fitmin = TMath::MinElement(graph->GetN(),graph->GetX());
+  // std::cout << "fitmin" << fitmin << std::endl;
+  
+  auto fitmax = TMath::MaxElement(graph->GetN(),graph->GetX());
+  // std::cout << "fitmax " << fitmax << std::endl;
+    
+  TF1 *fitfuncTOA = new TF1("fitfuncTOA","(([2]/(x-[0]))+ [1])",fitmin,fitmax);
+  fitfuncTOA->SetParNames("asymtote","offset","curvature");
+  
+  int iymax=TMath::LocMax(graph->GetN(),graph->GetY());
+  // cout << "iymax " << iymax << std::endl;
+  auto ttoa = graph->GetPointX(iymax);
+  // cout << "ttoa" << " " << ttoa << std::endl;;
+  fitfuncTOA->SetParameter(0,ttoa);
+  
+  auto xmax = TMath::MaxElement(graph->GetN(),graph->GetX());
+  auto dtoa = graph->Eval(xmax);
+  // cout << "dtoa" << " " << dtoa <<std::endl;
+  fitfuncTOA->SetParameter(1,dtoa);
+  
+  auto testx = 0.5*fitmax;
+  auto ctoa_y = graph->Eval(testx);
+  auto ctoa = (ctoa_y - dtoa)*(testx - ttoa);
+  // cout << "ctoa" << " " << ctoa <<std::endl;
+  fitfuncTOA->SetParameter(2,ctoa);
+  
+  gStyle->SetOptFit(1111);
+  fitfuncTOA->SetLineColor(kRed);
+  graph->Fit(fitfuncTOA,"R");
+  graph->GetXaxis()->SetTitle("Volatge[mV]");
+  graph->GetYaxis()->SetTitle ("time difference[ns]");
+  graph->SetTitle(" ");
+  graph->SetMarkerStyle(7);
+  graph->Draw("AP");
+   
+}
+
+void TreeEnergyWrite(){
+
+
+  int Ecol1;
+  double Ecol2,Ecol3,Ecol4;
+  string line_E;
+   
+  
+  TFile* Efile = new TFile("Energy_table.root","recreate");
+  TTree* ETree = new TTree("ETree","Energy tree");
+
+  ETree->Branch("Ecol1",&Ecol1,"Ecol1/I"); // ECol1 = Energy values = {200,300.....14000}
+  ETree->Branch("Ecol4",&Ecol4,"Ecol4/D"); // Voltage values 
+
+  std::ifstream Energy_file("Energy_table.dat");
+  if(Energy_file.is_open()){
+    while(getline(Energy_file,line_E)){
+      istringstream ssE(line_E);
+      ssE >> Ecol1 >> Ecol2 >> Ecol3 >> Ecol4;
+      ETree->Fill();
+    }
+  }
+
+  ETree->Write();
+  Efile->Close();
+  
+}
+
+void TreeTPWrite(){
+ 
+  int energy, col, row, pc;
+  double voltage,tot, tot_var, toa, toa_var, time_ref,toa_cut,mean,RMS;
+  string line_TP;
+
+  TFile* Efile = new TFile("Energy_table.root");
+  TTree* ETree = (TTree*)Efile->Get("ETree");
+  ETree->SetBranchAddress("Ecol1",&energy);
+  ETree->SetBranchAddress("Ecol4",&voltage);
+
+  
+  TFile* TPfile = new TFile("TP.root","update");  
+  TTree* TPtree = new TTree("TPtree"," TP tree");
+  TPtree->Branch("col",&col,"col/I");
+  TPtree->Branch("row",&row,"row/I");
+  TPtree->Branch("pc",&pc,"pc/I");
+  TPtree->Branch("tot",&tot,"tot/D");
+  TPtree->Branch("tot_var",&tot_var,"tot_var/D");
+  TPtree->Branch("toa",&toa,"toa/D");
+  TPtree->Branch("toa_var",&toa_var,"toa_var/D");
+  TPtree->Branch("time_ref",&time_ref,"time_ref/D");
+  auto voltageBranch = TPtree->Branch("voltage",&voltage,"voltage/D");// make a new branch and connect it to the same variable as the branch address of the energy tree
+  auto Branch_toacut = TPtree->Branch("toa_cut",&toa_cut,"toa_cut/D");
+
+  for(int i = 0; i < ETree->GetEntries(); i++){
+    ETree->GetEntry(i);
+    // std:: cout << energy << " " << voltage << std::endl;
+    std::string TPfilename = "tp_dat_" + std::to_string(energy) + ".dat";
+    //std:: cout << " The TPfilenames are : " <<  TPfilename.c_str() <<std::endl;
+    std::ifstream TPdatafile(TPfilename.c_str());
+
+    voltageBranch->Fill();
+    
+    if(TPdatafile.is_open()){
+
+      std::cout << " The data file " << TPfilename.c_str() << " is opened ..." <<std::endl;
+
+      
+      // reading through individial tp_dat_ files
+
+      while(getline(TPdatafile,line_TP)){
+	  if(line_TP.rfind("#", 0) == 0) {
+	    continue;
+	  }
+
+	  istringstream ssTP(line_TP);
+	  ssTP >> col >> row >> pc >> tot >> tot_var >> toa >> toa_var >> time_ref;
+	  TPtree->Fill();
+      } //While loop getline
+    }//if statement TPdatafile open
+
+    TPtree->Draw("toa",Form("voltage==(%f)",voltage),"goff");
+    mean = TMath::Mean(TPtree->GetSelectedRows(), TPtree->GetV1());
+    RMS = TMath::RMS(TPtree->GetSelectedRows(), TPtree->GetV1());
+    // std::cout <<" mean " << mean << " RMS " << RMS <<std::endl;
+
+    /* for (int isigma=0; isigma < 15; isigma++){
+      std::cout << " cut at " << isigma << " times the RMS leaves : " 
+      << 100.0*TPtree->GetEntries(Form("toa<(%f) && voltage==(%f)",mean+isigma*RMS,voltage))/TPtree->GetEntries(Form("voltage==(%f)",voltage)) 
+      << " percentage of entries " << std::endl;
+      }*/
+
+    toa_cut = mean + 6*RMS;
+    Branch_toacut->Fill();
+    
+  }//For loop GetEntries
+
+  //Save only the new version of the tree 
+
+  TPtree->Write("",TObject::kOverwrite);
+  long N = TPtree->Draw("voltage:toa:sqrt(toa_var) ", "row==1 && col==10 && toa>0", "goff");
+  TGraphErrors *gr = new TGraphErrors(N,TPtree->GetV1(),TPtree->GetV2(),0,TPtree->GetV3());
+  timewalkfit(gr);
+   
+  TPfile->Close();
+}
+
+
+void onepixel_tree(){ 
+
+  TreeEnergyWrite();
+  TreeTPWrite();
+ 
+}