#include "RooAddPdf.h"
#include "RooWorkspace.h"
#include "RooPlot.h"
#include <RooFitResult.h>
#include <RooCBShape.h>
#include <RooDataSet.h>
#include <RooDataHist.h>
#include "TCanvas.h"
#include "TAxis.h"
#include "TFile.h"
#include "TH1.h"
#include <RooBreitWigner.h>
#include <RooGenericPdf.h>
#include "RooHistPdf.h"
#include "TTree.h"
#include "TROOT.h" 

void hepfile()   
{

using namespace RooFit;

/*

TFile *file1 = new TFile("HEPData-ins1725190-v3-root.root", "READ");


TH1* hh = (TH1*)file1->Get("Dielectron invariant mass spectrum/Hist1D_y1") ;

TTree* tree1 = (TTree*)file1->Get("Dielectron invariant mass spectrum/Hist1D_y1") ;

RooRealVar t("t","Reconstructed mass", 1800,2500);

//RooDataHist data("data","dataset with x", mass,hh) ;

//RooDataSet data1("data1", "data1",  tree1, mass );

*/


// Observable

RooRealVar t("t","Reconstructed mass", 1800,2500);

// Theoretical model
RooRealVar ml("ml","mean landau", 3.14 ) ;

RooAbsPdf* myPdf = RooClassFactory::makePdfInstance("RooMyPdf", " (2*t) / (3.1415*sqrt(abs((t*t - 2000*2000)*(2098*2098 - t*t))))", RooArgSet(t)) ;


// Detector response function
RooRealVar mg("mg","mg", 0 ) ;
RooRealVar sg("sg","sg", 0.03, 0.01, 0.1 ) ;
RooGaussian gauss("gauss","gauss",t, mg, sg) ; 


//t.setBins(100) ;
RooFFTConvPdf lxg("lxg","landau (X) gauss",t, *myPdf, gauss) ; 

RooDataSet* data = lxg.generate(t,10000) ;


RooPlot* frame = t.frame() ;
data->plotOn(frame) ;  
myPdf->plotOn(frame,LineStyle(kDashed), LineColor(kRed), Normalization(1.0));
lxg.plotOn(frame, Normalization(1.0));
frame->Draw();





}