Author: Anna Kreshuk, Muriel Pivc
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Monday, June 27, 2022 at 10:05 AM.
%%cpp -d
#include "TSPlot.h"
#include "TTree.h"
#include "TH1.h"
#include "TCanvas.h"
#include "TFile.h"
#include "TPaveLabel.h"
#include "TPad.h"
#include "TPaveText.h"
#include "Riostream.h"
TString dir = gSystem->UnixPathName(__FILE__);
dir.ReplaceAll("TestSPlot.C","");
dir.ReplaceAll("/./","/");
TString dataFile = Form("%sTestSPlot_toyMC.dat",dir.Data());
Read the data and initialize a tsplot object
TTree *datatree = new TTree("datatree", "datatree");
datatree->ReadFile(dataFile,
"Mes/D:dE/D:F/D:MesSignal/D:MesBackground/D:dESignal/D:dEBackground/D:FSignal/D:FBackground/D",' ');
TSPlot *splot = new TSPlot(0, 3, 5420, 2, datatree);
Set the selection for data tree Note the order of the variables: first the control variables (not presented in this example), then the 3 discriminating variables, then their probability distribution functions for the first species(signal) and then their pdfs for the second species(background)
splot->SetTreeSelection(
"Mes:dE:F:MesSignal:dESignal:FSignal:MesBackground:"
"dEBackground:FBackground");
Set the initial estimates of the number of events in each species
Int_t ne[2];
ne[0]=500; ne[1]=5000;
splot->SetInitialNumbersOfSpecies(ne);
Compute the weights
splot->MakeSPlot();
Fill the splots
splot->FillSWeightsHists(25);
Now let's look at the splots The first two histograms are sPlots for the Mes variable signal and background. dE and F were chosen as discriminating variables to determine N1 and N2, through a maximum Likelihood fit, and thus the sPlots for the control variable Mes, unknown to the fit, was constructed. One can see that the sPlot for signal reproduces the PDF correctly, even when the latter vanishes.
The lower two histograms are sPlots for the F variables signal and background. dE and Mes were chosen as discriminating variables to determine N1 and N2, through a maximum Likelihood fit, and thus the sPlots for the control variable F, unknown to the fit, was constructed.
TCanvas *myc = new TCanvas("myc",
"sPlots of Mes and F signal and background", 800, 600);
myc->SetFillColor(40);
TPaveText *pt = new TPaveText(0.02,0.85,0.98,0.98);
pt->SetFillColor(18);
pt->SetTextFont(20);
pt->SetTextColor(4);
pt->AddText("sPlots of Mes and F signal and background,");
pt->AddText("obtained by the tutorial TestSPlot.C on BABAR MC "
"data (sPlot_toyMC.fit)");
TText *t3=pt->AddText(
"M. Pivk and F. R. Le Diberder, Nucl.Inst.Meth.A, physics/0402083");
t3->SetTextColor(1);
t3->SetTextFont(30);
pt->Draw();
TPad* pad1 = new TPad("pad1","Mes signal",0.02,0.43,0.48,0.83,33);
TPad* pad2 = new TPad("pad2","Mes background",0.5,0.43,0.98,0.83,33);
TPad* pad3 = new TPad("pad3", "F signal", 0.02, 0.02, 0.48, 0.41,33);
TPad* pad4 = new TPad("pad4", "F background", 0.5, 0.02, 0.98, 0.41,33);
pad1->Draw();
pad2->Draw();
pad3->Draw();
pad4->Draw();
pad1->cd();
pad1->SetGrid();
TH1D *sweight00 = splot->GetSWeightsHist(-1, 0, 0);
sweight00->SetTitle("Mes signal");
sweight00->SetStats(kFALSE);
sweight00->Draw("e");
sweight00->SetMarkerStyle(21);
sweight00->SetMarkerSize(0.7);
sweight00->SetMarkerColor(2);
sweight00->SetLineColor(2);
sweight00->GetXaxis()->SetLabelSize(0.05);
sweight00->GetYaxis()->SetLabelSize(0.06);
sweight00->GetXaxis()->SetLabelOffset(0.02);
pad2->cd();
pad2->SetGrid();
TH1D *sweight10 = splot->GetSWeightsHist(-1, 1, 0);
sweight10->SetTitle("Mes background");
sweight10->SetStats(kFALSE);
sweight10->Draw("e");
sweight10->SetMarkerStyle(21);
sweight10->SetMarkerSize(0.7);
sweight10->SetMarkerColor(2);
sweight10->SetLineColor(2);
sweight10->GetXaxis()->SetLabelSize(0.05);
sweight10->GetYaxis()->SetLabelSize(0.06);
sweight10->GetXaxis()->SetLabelOffset(0.02);
pad3->cd();
pad3->SetGrid();
TH1D *sweight02 = splot->GetSWeightsHist(-1, 0, 2);
sweight02->SetTitle("F signal");
sweight02->SetStats(kFALSE);
sweight02->Draw("e");
sweight02->SetMarkerStyle(21);
sweight02->SetMarkerSize(0.7);
sweight02->SetMarkerColor(2);
sweight02->SetLineColor(2);
sweight02->GetXaxis()->SetLabelSize(0.06);
sweight02->GetYaxis()->SetLabelSize(0.06);
sweight02->GetXaxis()->SetLabelOffset(0.01);
pad4->cd();
pad4->SetGrid();
TH1D *sweight12 = splot->GetSWeightsHist(-1, 1, 2);
sweight12->SetTitle("F background");
sweight12->SetStats(kFALSE);
sweight12->Draw("e");
sweight12->SetMarkerStyle(21);
sweight12->SetMarkerSize(0.7);
sweight12->SetMarkerColor(2);
sweight12->SetLineColor(2);
sweight12->GetXaxis()->SetLabelSize(0.06);
sweight12->GetYaxis()->SetLabelSize(0.06);
sweight02->GetXaxis()->SetLabelOffset(0.01);
myc->cd();
Draw all canvases
%jsroot on
gROOT->GetListOfCanvases()->Draw()