draw_charge_space_coarse_II.cxx

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#include <fstream>
TString rootfilelist("rootfile_list.txt");
bool m_debug = false;
const double m_err_standard = 0.005;
const double m_diff_standard = 0.02;
int m_num_in_bin = 100;
int m_num_hists = 0;
double x[1000], xerr[1000], y[1000], yerr[1000];
 
double f_real_work(){
  // read input file
  ifstream input_file(rootfilelist);
  if(!input_file){
    cout << "cannot read input file correctly!" << endl;
    exit();
  }
  TString rootfilename("begin");
  TH1F *hx[1000];
  TH1F *h[1000];
  for(int j=0; j<1000; j++){
    h[j] = new TH1F(Form("h%d",j), "h", 3000, 0, 1000);
    hx[j] = new TH1F(Form("hx%d",j), "hx", 100000, 0, 100000);
  }
 
  while(rootfilename!=""){
    input_file >> rootfilename;
    if(m_debug) cout << rootfilename << endl;
    else if(m_num_hists%50==0){
      cout << rootfilename << endl;
      cout << "num of hists " << m_num_hists+1 << endl;
    }
    if(rootfilename=="") continue;
    TFile *f = new TFile(rootfilename);
    if(!f) continue;
    TTree *t = f->Get("n103");
    float runno(0);
    float dedx(0), costheta(0);
    t->SetBranchAddress("runNO", &runno);
    t->SetBranchAddress("dEdx_meas", &dedx);
    t->SetBranchAddress("costheta", &costheta);
    for(int i=0; i<t->GetEntries(); i++){
      t->GetEntry(i);
      if(i==0) hx[m_num_hists]->Fill(runno);
      if(fabs(costheta)<0.15) h[m_num_hists]->Fill(dedx);
    }
    if(h[m_num_hists]->GetEntries()>m_num_in_bin) m_num_hists ++;
    delete t;
    delete f;
  }
  double m_ave_err(0);
  for(int k=0; k<m_num_hists; k++){
    x[k] = hx[k]->GetMean();
    xerr[k] = hx[k]->GetRMS();
    y[k] = h[k]->GetMean();
    yerr[k] = h[k]->GetMeanError();
    m_ave_err += yerr[k]/y[k];
  }
  m_ave_err = m_ave_err/m_num_hists;
  return m_ave_err;
}
 
 
void draw_charge_space_coarse_II(){
  double m_error = f_real_work();
  if(m_error>m_err_standard){
    m_num_hists = 0;
    m_num_in_bin = (int)pow(m_error/m_err_standard,2)*m_num_in_bin;
    cout << "new num of bin: " << m_num_in_bin << endl;
    m_error = f_real_work();
  }
  cout << "average error: " << m_error << endl;
 
  TGraphErrors *g = new TGraphErrors(m_num_hists, x, y ,xerr, yerr);
  TCanvas *c1 = new TCanvas("c1", "c1", 10, 10, 800, 642);
  g->Draw("AP");
  for(int k=0; k<m_num_hists; k++){
    if(fabs(y[k+1]-y[k])/y[k]>m_diff_standard){
      TLine *l = new TLine(x[k+1]-xerr[k+1], y[k+1]-5*(yerr[k+1]), x[k+1]-xerr[k+1], y[k+1]+5*(yerr[k+1]));
      l->SetLineColor(2);
      l->Draw();
    }
  }
  c1->SaveAs("figs/charge_space_via_run_coarse_II.eps");
  c1->SaveAs("figs/charge_space_via_run_coarse_II.root");
 
}