vtxFit.cxx

Go to the documentation of this file.

void vtxFit() {
 
  Double_t chik, kvx, kvy, kvz, ndofk, probk;
  TChain* t = new TChain("kalvtx");
  t->Add("run_0009903_dst_pvtx2.root");
  t->Add("run_0009903_dst_pvtx3.root");
  t->SetBranchAddress("chik", &chik );
  t->SetBranchAddress("kvx",  &kvx  );
  t->SetBranchAddress("kvy",  &kvy  );
  t->SetBranchAddress("kvz",  &kvz  );
  t->SetBranchAddress("ndofk",  &ndofk );
  t->SetBranchAddress("probk",   &probk );
 
  Int_t nentries = (Int_t) t->GetEntries();
 
  TH1D* m_vertex_x_kal = new TH1D("x of vertex in kal", "x of vertex in kal", 60, -0.6, 0.6);
  TH1D* m_vertex_y_kal = new TH1D("y of vertex in kal", "y of vertex in kal", 60, -0.6, 0.1);
  TH1D* m_vertex_z_kal = new TH1D("z of vertex in kal", "z of vertex in kal", 60, -6, 6);
    
  for( Int_t i=0; i<nentries; i++ ) {
    t->GetEntry(i);
    m_vertex_x_kal->Fill(kvx);
    m_vertex_y_kal->Fill(kvy);
    m_vertex_z_kal->Fill(kvz);
  }
 
 
  TCanvas *myC = new TCanvas("myC", "myC", 1200, 400);
  TPad *background = (TPad*)gPad;
  background->SetFillColor(10);
  myC->Divide(3,1);
  myC->cd(1);
 
  TF1 *func = new TF1("func", "gaus", -0.6, 0.6);
  m_vertex_x_kal->Fit("func", "R+");
  Double_t MeanXKal = func->GetParameter(1);
  Double_t SigmaXKal = func->GetParameter(2);
  Double_t ErrMeanXKal = func->GetParError(1);
  Double_t ErrSigmaXKal = func->GetParError(2);
 
  myC->cd(2);
  TF1 *funcY = new TF1("funcY", "gaus", -0.6, 0.1);
  m_vertex_y_kal->Fit("funcY", "R+");
  Double_t MeanYKal = funcY->GetParameter(1);
  Double_t SigmaYKal = funcY->GetParameter(2);
  Double_t ErrMeanYKal = funcY->GetParError(1);
  Double_t ErrSigmaYKal = funcY->GetParError(2);
 
  myC->cd(3);
  TF1 *funcZ = new TF1("funcZ", "gaus", -6, 6);
  m_vertex_z_kal->Fit("funcZ", "R+");
  Double_t MeanZKal = funcZ->GetParameter(1);
  Double_t SigmaZKal = funcZ->GetParameter(2); 
  Double_t ErrMeanZKal = funcZ->GetParError(1);
  Double_t ErrSigmaZKal = funcZ->GetParError(2);
  
  cout << "Kal: Mean X, Y, Z = "<<MeanXKal << "  " << MeanYKal << "  " << MeanZKal << endl;
  cout << "Kal: Sigma X, Y, Z = "<<SigmaXKal<<"  " <<SigmaYKal <<"  " << SigmaZKal << endl;
 
  figs_name = "figs.ps";
  myC->SaveAs(figs_name);
 
  //ofstream file(file_name);
 
  cout << MeanXKal << " "<< MeanYKal << " "<< MeanZKal << " "<< SigmaXKal << " " << SigmaYKal << " " << SigmaZKal << endl;
  cout << ErrMeanXKal << " " << ErrMeanYKal<< " " << ErrMeanZKal << " " << ErrSigmaXKal << " " << ErrSigmaYKal << " " << ErrSigmaZKal << endl;
 
          
  return;
 
}