doc/v606/rf304__uncorrprod_8C.html

#ifndef __CINT__

#include "RooGlobalFunc.h"

#endif

#include "RooRealVar.h"

#include "RooDataSet.h"

#include "RooGaussian.h"

#include "RooProdPdf.h"

#include "TCanvas.h"

#include "TAxis.h"

#include "RooPlot.h"

using namespace RooFit ;


void rf304_uncorrprod()

{


  // C r e a t e   c o m p o n e n t   p d f s   i n   x   a n d   y

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


  // Create two p.d.f.s gaussx(x,meanx,sigmax) gaussy(y,meany,sigmay) and its variables

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

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


  RooRealVar meanx("mean1","mean of gaussian x",2) ;

  RooRealVar meany("mean2","mean of gaussian y",-2) ;

  RooRealVar sigmax("sigmax","width of gaussian x",1) ;

  RooRealVar sigmay("sigmay","width of gaussian y",5) ;


  RooGaussian gaussx("gaussx","gaussian PDF",x,meanx,sigmax) ;

  RooGaussian gaussy("gaussy","gaussian PDF",y,meany,sigmay) ;


  // C o n s t r u c t   u n c o r r e l a t e d   p r o d u c t   p d f

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


  // Multiply gaussx and gaussy into a two-dimensional p.d.f. gaussxy

  RooProdPdf  gaussxy("gaussxy","gaussx*gaussy",RooArgList(gaussx,gaussy)) ;


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

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


  // Generate 10000 events in x and y from gaussxy

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


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

  RooPlot* xframe = x.frame(Title("X projection of gauss(x)*gauss(y)")) ;

  data->plotOn(xframe) ;

  gaussxy.plotOn(xframe) ;


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

  RooPlot* yframe = y.frame(Title("Y projection of gauss(x)*gauss(y)")) ;

  data->plotOn(yframe) ;

  gaussxy.plotOn(yframe) ;


  // Make canvas and draw RooPlots

  TCanvas *c = new TCanvas("rf304_uncorrprod","rf304_uncorrprod",800, 400);

  c->Divide(2);

  c->cd(1) ; gPad->SetLeftMargin(0.15) ; xframe->GetYaxis()->SetTitleOffset(1.4) ; xframe->Draw() ;

  c->cd(2) ; gPad->SetLeftMargin(0.15) ; yframe->GetYaxis()->SetTitleOffset(1.4) ; yframe->Draw() ;


}