Multidimensional models: projecting pdf and data slices in discrete observables
Author: Wouter Verkerke
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Wednesday, April 17, 2024 at 11:18 AM.
%%cpp -d
#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussModel.h"
#include "RooDecay.h"
#include "RooBMixDecay.h"
#include "RooCategory.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "RooPlot.h"
using namespace RooFit;
Decay time observables
RooRealVar dt("dt", "dt", -20, 20);
Discrete observables mixState (B0tag==B0reco?) and tagFlav (B0tag==B0(bar)?)
RooCategory mixState("mixState", "B0/B0bar mixing state");
RooCategory tagFlav("tagFlav", "Flavour of the tagged B0");
Define state labels of discrete observables
mixState.defineType("mixed", -1);
mixState.defineType("unmixed", 1);
tagFlav.defineType("B0", 1);
tagFlav.defineType("B0bar", -1);
Model parameters
RooRealVar dm("dm", "delta m(B)", 0.472, 0., 1.0);
RooRealVar tau("tau", "B0 decay time", 1.547, 1.0, 2.0);
RooRealVar w("w", "Flavor Mistag rate", 0.03, 0.0, 1.0);
RooRealVar dw("dw", "Flavor Mistag rate difference between B0 and B0bar", 0.01);
Build a gaussian resolution model
RooRealVar bias1("bias1", "bias1", 0);
RooRealVar sigma1("sigma1", "sigma1", 0.01);
RooGaussModel gm1("gm1", "gauss model 1", dt, bias1, sigma1);
Construct a decay pdf, smeared with single gaussian resolution model
RooBMixDecay bmix_gm1("bmix", "decay", dt, mixState, tagFlav, tau, dm, w, dw, gm1, RooBMixDecay::DoubleSided);
Generate BMixing data with above set of event errors
std::unique_ptr<RooDataSet> data{bmix_gm1.generate({dt, tagFlav, mixState}, 20000)};
input_line_60:2:2: warning: 'data' shadows a declaration with the same name in the 'std' namespace; use '::data' to reference this declaration std::unique_ptr<RooDataSet> data{bmix_gm1.generate({dt, tagFlav, mixState}, 20000)}; ^
Create frame, plot data and pdf projection (integrated over tagFlav and mixState)
RooPlot *frame = dt.frame(Title("Inclusive decay distribution"));
data->plotOn(frame);
bmix_gm1.plotOn(frame);
input_line_61:3:1: error: reference to 'data' is ambiguous data->plotOn(frame); ^ input_line_60:2:30: note: candidate found by name lookup is 'data' std::unique_ptr<RooDataSet> data{bmix_gm1.generate({dt, tagFlav, mixState}, 20000)}; ^ /usr/include/c++/9/bits/range_access.h:318:5: note: candidate found by name lookup is 'std::data' data(initializer_list<_Tp> __il) noexcept ^ /usr/include/c++/9/bits/range_access.h:289:5: note: candidate found by name lookup is 'std::data' data(_Container& __cont) noexcept(noexcept(__cont.data())) ^ /usr/include/c++/9/bits/range_access.h:299:5: note: candidate found by name lookup is 'std::data' data(const _Container& __cont) noexcept(noexcept(__cont.data())) ^ /usr/include/c++/9/bits/range_access.h:309:5: note: candidate found by name lookup is 'std::data' data(_Tp (&__array)[_Nm]) noexcept ^
Create frame, plot data (mixed only)
RooPlot *frame2 = dt.frame(Title("Decay distribution of mixed events"));
data->plotOn(frame2, Cut("mixState==mixState::mixed"));
input_line_62:3:1: error: reference to 'data' is ambiguous data->plotOn(frame2, Cut("mixState==mixState::mixed")); ^ input_line_60:2:30: note: candidate found by name lookup is 'data' std::unique_ptr<RooDataSet> data{bmix_gm1.generate({dt, tagFlav, mixState}, 20000)}; ^ /usr/include/c++/9/bits/range_access.h:318:5: note: candidate found by name lookup is 'std::data' data(initializer_list<_Tp> __il) noexcept ^ /usr/include/c++/9/bits/range_access.h:289:5: note: candidate found by name lookup is 'std::data' data(_Container& __cont) noexcept(noexcept(__cont.data())) ^ /usr/include/c++/9/bits/range_access.h:299:5: note: candidate found by name lookup is 'std::data' data(const _Container& __cont) noexcept(noexcept(__cont.data())) ^ /usr/include/c++/9/bits/range_access.h:309:5: note: candidate found by name lookup is 'std::data' data(_Tp (&__array)[_Nm]) noexcept ^
Position slice in mixState at "mixed" and plot slice of pdf in mixstate over data (integrated over tagFlav)
bmix_gm1.plotOn(frame2, Slice(mixState, "mixed"));
input_line_63:2:26: error: cannot initialize an array element of type 'void *' with an rvalue of type 'RooCmdArg (*)(RooCategory &, const char *)' bmix_gm1.plotOn(frame2, Slice(mixState, "mixed")); ^~~~~
Create frame, plot data (unmixed only)
RooPlot *frame3 = dt.frame(Title("Decay distribution of unmixed events"));
data->plotOn(frame3, Cut("mixState==mixState::unmixed"));
input_line_64:3:1: error: reference to 'data' is ambiguous data->plotOn(frame3, Cut("mixState==mixState::unmixed")); ^ input_line_60:2:30: note: candidate found by name lookup is 'data' std::unique_ptr<RooDataSet> data{bmix_gm1.generate({dt, tagFlav, mixState}, 20000)}; ^ /usr/include/c++/9/bits/range_access.h:318:5: note: candidate found by name lookup is 'std::data' data(initializer_list<_Tp> __il) noexcept ^ /usr/include/c++/9/bits/range_access.h:289:5: note: candidate found by name lookup is 'std::data' data(_Container& __cont) noexcept(noexcept(__cont.data())) ^ /usr/include/c++/9/bits/range_access.h:299:5: note: candidate found by name lookup is 'std::data' data(const _Container& __cont) noexcept(noexcept(__cont.data())) ^ /usr/include/c++/9/bits/range_access.h:309:5: note: candidate found by name lookup is 'std::data' data(_Tp (&__array)[_Nm]) noexcept ^
Position slice in mixState at "unmixed" and plot slice of pdf in mixstate over data (integrated over tagFlav)
bmix_gm1.plotOn(frame3, Slice(mixState, "unmixed"));
TCanvas *c = new TCanvas("rf310_sliceplot", "rf310_sliceplot", 1200, 400);
c->Divide(3);
c->cd(1);
gPad->SetLeftMargin(0.15);
frame->GetYaxis()->SetTitleOffset(1.4);
gPad->SetLogy();
frame->Draw();
c->cd(2);
gPad->SetLeftMargin(0.15);
frame2->GetYaxis()->SetTitleOffset(1.4);
gPad->SetLogy();
frame2->Draw();
c->cd(3);
gPad->SetLeftMargin(0.15);
frame3->GetYaxis()->SetTitleOffset(1.4);
gPad->SetLogy();
frame3->Draw();
input_line_65:2:26: error: cannot initialize an array element of type 'void *' with an rvalue of type 'RooCmdArg (*)(RooCategory &, const char *)' bmix_gm1.plotOn(frame3, Slice(mixState, "unmixed")); ^~~~~
Draw all canvases
gROOT->GetListOfCanvases()->Draw()