mcr/calib/tofino/DetermineKaonThreshold.C

/*
======================================================================
  DetermineKaonThreshold(TString const &filename)
    Read a root file (produced by TofinoStability) and find the threshold
    for kaons in the sqrt(ADCe*ADCp) spectrum of high threshold.
======================================================================
*/
#include <iostream>
#include "TH1.h"
#include "TF1.h"
#include "TFile.h"
#include "TStyle.h"
#include "TCanvas.h"
#include "TPad.h"
#include "TArrow.h"

void DetermineKaonThreshold(TString const &filename){
  gStyle->SetOptFit(1);
  TFile *f=new TFile(filename);
  if (!f){
    cout << "File does not exist." << endl;
    return;
  }
  TH1F *AdcSqr[12];
  TArrow *th_arrow[12];
  TString hname;
  TF1 *fit_func, *landau_fit;
  Int_t threshold[12];
  TCanvas *c1=new TCanvas("c1","c1",0,0,800,640);
  c1->Divide(3,2);
  TCanvas *c2=new TCanvas("c2","c2",0,0,800,640);
  c2->Divide(3,2);
  //  TPad *pad1=new TPad("pad1","pad1",0,0,1,1);
//    pad1->SetFillStyle(4000);
//    pad1->Draw();
//    pad1->cd();
  for (Int_t sl=0; sl<12; sl++){
    if (sl<6) c1->cd(sl+1);
    else c2->cd(sl-5);
    hname="TofinoAdcKaonSqrAll_";
    hname+=(sl+1);
    AdcSqr[sl]=(TH1F*) f->Get(hname);
    if (!AdcSqr[sl]){
      cout << "Input root file is too old... Make a updated one!" << endl;
      return;
    }
    fit_func=new TF1("fit_func", "landau(0)+landau(3)",0,1200);
    fit_func->SetParameter(0,1000);
    fit_func->SetParameter(1,200);
    fit_func->SetParLimits(1,200,400);
    fit_func->SetParameter(2,100);
    fit_func->SetParLimits(2,0,400);
    fit_func->SetParameter(3,10000);
    fit_func->SetParameter(4,800);
    fit_func->SetParLimits(4,500,1000);
    fit_func->SetParameter(5,100);
    fit_func->SetParLimits(5,30,100);
    AdcSqr[sl]->Fit("fit_func","Q","",0,1200);
    //   AdcSqr[sl]->Fit("landau","","",0,1200);
    AdcSqr[sl]->Draw();

    landau_fit=new TF1("landau_fit","landau(0)",0,1200);
    landau_fit->SetParameter(0,fit_func->GetParameter(3));
    landau_fit->SetParameter(1,fit_func->GetParameter(4));
    landau_fit->SetParameter(2,fit_func->GetParameter(5));
    landau_fit->SetLineColor(kRed);
    landau_fit->Draw("same");
    Double_t landau_x=fit_func->GetParameter(4), landau_y;
    Double_t maxy=landau_fit->Eval(landau_x);
    do{
      landau_x-=0.1;
      landau_y=landau_fit->Eval(landau_x);
    } while (landau_y>maxy*0.01);
    threshold[sl]=(Int_t) landau_x;
     th_arrow[sl] = new TArrow(threshold[sl], 0.05*AdcSqr[sl]->GetMaximum(),
                              threshold[sl], 0.5*AdcSqr[sl]->GetMaximum(),
                              0.02,"<|");
    th_arrow[sl]->SetLineWidth(2);
    th_arrow[sl]->SetLineColor(kBlue);
    th_arrow[sl]->SetFillColor(kBlue);
    th_arrow[sl]->Draw();
    //    pad1->Modified();
    //    c1->Update();    
    cout << "Slab " << sl+1 << " : threshold=" << threshold[sl] << endl;
  }}

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