%%cpp -d
#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "RooConstVar.h"
#include "RooExponential.h"
#include "RooEffProd.h"
#include "RooFormulaVar.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "RooPlot.h"
using namespace RooFit;

RooRealVar t("t", "t", 0, 5);

RooRealVar tau("tau", "tau", -1.54, -4, -0.1);
RooExponential model("model", "model", t, tau);

RooFormulaVar eff("eff", "0.5*(TMath::Erf((t-1)/0.5)+1)", t);

RooEffProd modelEff("modelEff", "model with efficiency", model, eff);

RooPlot *frame1 = t.frame(Title("Efficiency"));
eff.plotOn(frame1, LineColor(kRed));

RooPlot *frame2 = t.frame(Title("Pdf with and without efficiency"));

model.plotOn(frame2, LineStyle(kDashed));
modelEff.plotOn(frame2);

std::unique_ptr<RooDataSet> data{modelEff.generate(t, 10000)};

modelEff.fitTo(*data, PrintLevel(-1));

RooPlot *frame3 = t.frame(Title("Fitted pdf with efficiency"));
data->plotOn(frame3);
modelEff.plotOn(frame3);

TCanvas *c = new TCanvas("rf703_effpdfprod", "rf703_effpdfprod", 1200, 400);
c->Divide(3);
c->cd(1);
gPad->SetLeftMargin(0.15);
frame1->GetYaxis()->SetTitleOffset(1.4);
frame1->Draw();
c->cd(2);
gPad->SetLeftMargin(0.15);
frame2->GetYaxis()->SetTitleOffset(1.6);
frame2->Draw();
c->cd(3);
gPad->SetLeftMargin(0.15);
frame3->GetYaxis()->SetTitleOffset(1.6);
frame3->Draw();

%jsroot on
gROOT->GetListOfCanvases()->Draw()