Kalanand's March 2009 Log

March 3rd

Computing cosine θ* for the system X → YZ

Float_t CosThetaStar(TLorentzVector *daughter, TLorentzVector *parent)
{
  // angle between mother and daughter in mother's rest frame
  
  TVector3 boostvect = -(*parent).BoostVector();

  //boost the daughter to mother's rest frame
  (*daughter).Boost(boostvect);

  // get the unit vectors for the mother and daughter
  TVector3 dunit = (*daughter).Vect().Unit();
  TVector3 punit = (*parent).Vect().Unit();

  // take their dot product
  return dunit.Dot(punit);
}

March 18th

Functions to plot n histograms on a canvas

// Plot on canvas: one histogram
TCanvas* PlotOnCanvas(TString plotname, TH1& h, char* drawOption="e") {
  TCanvas* can = new TCanvas( plotname, plotname, 500, 500 );
  gStyle->SetOptStat(0);
  h.Draw(drawOption);
  can->SaveAs( plotname+TString(".pdf") );
  return can;
}



// Plot on canvas: two histograms
TCanvas* PlotTwoOnCanvas(TString plotname, TH1& h1, TString label1,
TH1& h2, TString label2, float x0=0.63,
float y0=0.8, float x1=0.9, float y1=0.9,
char* opt1 = "HIST e", char* opt2 = "Hist esame") {
  
  double i1 = h1.Integral();
  double i2 = h2.Integral();
  
  TCanvas* can = new TCanvas( plotname, plotname, 500, 500 );
  gStyle->SetOptStat(0);
  if( !(i1==0.0 || i2==0.0) ) {
    h1.Draw("Hist e");
    h2.Draw("Hist esame");
  }
  else if(i2==0.0) h1.Draw("e");
  else h2.Draw("e");
  TLegend* leg = new TLegend(x0,y0,x1,y1);
  leg->AddEntry( &h1, label1,"L");
  leg->AddEntry( &h2, label2,"L");
  leg->SetMargin(0.15);
  leg->SetFillColor(0);
  if( !(i1==0.0 || i2==0.0) ) leg->Draw();
  // gPad->SetLogy();
 // gPad->SetGridx();
  can->SaveAs( plotname+TString(".pdf") );
  return can;
}


// Plot on canvas: three histograms
TCanvas* PlotThreeOnCanvas(TString plotname, TH1& h1, TString label1,
TH1& h2, TString label2, TH1& h3, TString label3,
float x0=0.63,
float y0=0.8, float x1=0.9, float y1=0.9) {
  
  TCanvas* can = new TCanvas( plotname, plotname, 500, 500 );
  h1.Draw("Hist e");
  h2.Draw("Hist esame");
  h3.Draw("Hist esame");
  TLegend* leg = new TLegend(x0,y0,x1,y1);
  leg->AddEntry( &h1, label1,"L");
  leg->AddEntry( &h2, label2,"L");
  leg->AddEntry( &h3, label3,"L");
  leg->SetMargin(0.15);
  leg->SetFillColor(0);
  leg->Draw();
  // gPad->SetLogy();
  gPad->SetGridx();
  can->SaveAs( plotname+TString(".pdf") );
  return can;
}


// Plot on canvas: four histograms
TCanvas* PlotFourOnCanvas(TString plotname, TH1& h1, TString label1,
TH1& h2, TString label2, TH1& h3, TString label3,
TH1& h4, TString label4, float x0=0.63,
float y0=0.8, float x1=0.9, float y1=0.9) {
  
  TCanvas* can = new TCanvas( plotname, plotname, 500, 500 );
  h1.Draw("Hist e");
  h2.Draw("Hist esame");
  h3.Draw("Hist esame");
  h4.Draw("Hist esame");
  TLegend* leg = new TLegend(x0,y0,x1,y1);
  leg->AddEntry( &h1, label1,"L");
  leg->AddEntry( &h2, label2,"L");
  leg->AddEntry( &h3, label3,"L");
  leg->AddEntry( &h4, label4,"L");
  leg->SetMargin(0.15);
  leg->SetFillColor(0);
  leg->Draw();
  // gPad->SetLogy();
  // gPad->SetGridx();
  can->SaveAs( plotname+TString(".pdf") );
  return can;
}



// Plot on canvas: five histograms
TCanvas* PlotFiveOnCanvas(TString plotname, TH1& h1, TString label1,
TH1& h2, TString label2, TH1& h3, TString label3,
TH1& h4, TString label4, TH1& h5, TString label5,
float x0=0.63,
float y0=0.8, float x1=0.9, float y1=0.9) {
  
  TCanvas* can = new TCanvas( plotname, plotname, 500, 500 );
  h1.Draw("Hist e");
  h2.Draw("Hist esame");
  h3.Draw("Hist esame");
  h4.Draw("Hist esame");
  h5.Draw("Hist esame");
  TLegend* leg = new TLegend(x0,y0,x1,y1);
  leg->AddEntry( &h1, label1,"L");
  leg->AddEntry( &h2, label2,"L");
  leg->AddEntry( &h3, label3,"L");
  leg->AddEntry( &h4, label4,"L");
  leg->AddEntry( &h5, label5,"L");
  leg->SetMargin(0.15);
  leg->SetFillColor(0);
  leg->Draw();
  // gPad->SetLogy();
  gPad->SetGridx();
  can->SaveAs( plotname+TString(".pdf") );
  return can;
}

Go to February's log