#include <TROOT.h>
#include <TApplication.h>
#include <TSystem.h>
#include <TCanvas.h>
#include <TH1D.h>
#include <TStyle.h>
#include <TFile.h>
#include <TTree.h>
#include <TGaxis.h>
#include <TLegend.h>
#include <TPaveText.h>
#include <TLorentzVector.h>

#include <RooRealVar.h>
#include <RooGaussian.h>
#include <RooAddPdf.h>
#include <RooDataSet.h>
#include <RooGenericPdf.h>
#include <RooPlot.h>
#include <RooArgList.h>
#include <RooChebychev.h>
#include <RooFitResult.h>
#include <RooProdPdf.h>

#include <iostream>
#include <sstream>


using namespace RooFit;


void TestRooFit()
{
  stringstream myString;

  RooRealVar x("x","x",-10,10) ; 
  RooRealVar y("y","y",-10,10) ; 

  RooRealVar meanx("meanx","meanx",2,-10,10) ; 
  RooRealVar sigmax("sigmax","sigmax",1,0.,10.) ; 
  RooGaussian gaussx("gaussx","gaussx",x,meanx,sigmax) ; 
   
  RooRealVar meany("meany","meany",-2,-10,10) ; 
  RooRealVar sigmay("sigmay","sigmay",5,0.,10.) ; 
  RooGaussian gaussy("gaussy","gaussy",y,meany,sigmay) ; 
 

  x.setRange("Range",0,4);
  y.setRange("Range",-10,10);

  x.setRange("Whole",-10,10);
  y.setRange("Whole",-10,10);
 
  RooRealVar nS("nS","nS",1700) ; 
  RooRealVar nB("nB","nB",500) ; 
  nS.setConstant(kFALSE);
  nB.setConstant(kFALSE);
  RooAddPdf myPDF("myPDF","myPDF",RooArgList(gaussx,gaussy),RooArgList(nS,nB));

  RooDataSet* data = myPDF.generate(RooArgSet(x,y),10000) ; 
  myPDF.fitTo(*data,Extended(kTRUE),SumCoefRange("Range"), Range("Range")) ;
  myPDF.fixCoefRange("Range");

  TCanvas* Canv = new TCanvas("Canv","Canv",10, 10, 700, 900);
  Canv->Divide(1,2);
  Canv->cd(1);

  RooPlot* framex = x.frame(Range("Whole")) ; 
  data->plotOn(framex,CutRange("Range")) ; 
  myPDF.plotOn(framex,Range("Whole"),NormRange("Range")) ;

  framex->Draw();
  Canv->cd(2);

  RooPlot* framey = y.frame(Range("Whole")) ; 
  data->plotOn(framey,CutRange("Range")) ; 
  myPDF.plotOn(framey,Range("Whole"),NormRange("Range")) ;

  framey->Draw();
  Canv->Update();
}