doc/v606/rf305__condcorrprod_8C.html

#ifndef __CINT__

#include "RooGlobalFunc.h"

#endif

#include "RooRealVar.h"

#include "RooDataSet.h"

#include "RooGaussian.h"

#include "RooConstVar.h"

#include "RooPolyVar.h"

#include "RooProdPdf.h"

#include "RooPlot.h"

#include "TCanvas.h"

#include "TAxis.h"

#include "TH1.h"

using namespace RooFit ;


void rf305_condcorrprod()

{

  // C r e a t e   c o n d i t i o n a l   p d f   g x ( x | y )

  // -----------------------------------------------------------


  // Create observables

  RooRealVar x("x","x",-5,5) ;

  RooRealVar y("y","y",-5,5) ;


  // Create function f(y) = a0 + a1*y

  RooRealVar a0("a0","a0",-0.5,-5,5) ;

  RooRealVar a1("a1","a1",-0.5,-1,1) ;

  RooPolyVar fy("fy","fy",y,RooArgSet(a0,a1)) ;


  // Create gaussx(x,f(y),sx)

  RooRealVar sigmax("sigma","width of gaussian",0.5) ;

  RooGaussian gaussx("gaussx","Gaussian in x with shifting mean in y",x,fy,sigmax) ;


  // C r e a t e   p d f   g y ( y )

  // -----------------------------------------------------------


  // Create gaussy(y,0,5)

  RooGaussian gaussy("gaussy","Gaussian in y",y,RooConst(0),RooConst(3)) ;


  // C r e a t e   p r o d u c t   g x ( x | y ) * g y ( y )

  // -------------------------------------------------------


  // Create gaussx(x,sx|y) * gaussy(y)

  RooProdPdf model("model","gaussx(x|y)*gaussy(y)",gaussy,Conditional(gaussx,x)) ;


  // S a m p l e ,   f i t   a n d   p l o t   p r o d u c t   p d f

  // ---------------------------------------------------------------


  // Generate 1000 events in x and y from model

  RooDataSet *data = model.generate(RooArgSet(x,y),10000) ;


  // Plot x distribution of data and projection of model on x = Int(dy) model(x,y)

  RooPlot* xframe = x.frame() ;

  data->plotOn(xframe) ;

  model.plotOn(xframe) ;


  // Plot x distribution of data and projection of model on y = Int(dx) model(x,y)

  RooPlot* yframe = y.frame() ;

  data->plotOn(yframe) ;

  model.plotOn(yframe) ;


  // Make two-dimensional plot in x vs y

  TH1* hh_model = model.createHistogram("hh_model",x,Binning(50),YVar(y,Binning(50))) ;

  hh_model->SetLineColor(kBlue) ;


  // Make canvas and draw RooPlots

  TCanvas *c = new TCanvas("rf305_condcorrprod","rf05_condcorrprod",1200, 400);

  c->Divide(3);

  c->cd(1) ; gPad->SetLeftMargin(0.15) ; xframe->GetYaxis()->SetTitleOffset(1.6) ; xframe->Draw() ;

  c->cd(2) ; gPad->SetLeftMargin(0.15) ; yframe->GetYaxis()->SetTitleOffset(1.6) ; yframe->Draw() ;

  c->cd(3) ; gPad->SetLeftMargin(0.20) ; hh_model->GetZaxis()->SetTitleOffset(2.5) ; hh_model->Draw("surf") ;


}