#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "RooPlot.h"
#include "RooAddPdf.h"
#include "TH1.h"
#include "RooGaussian.h"
#include "RooFormulaVar.h"
#include "RooAbsPdf.h"
#include "TFormula.h"
#include "RooEffProd.h"
#include "TLine.h"
#include "RooNumConvolution.h"
#include "RooCFunction4Binding.h"
//#if
//#endif
using namespace RooFit;

void code() {

	RooRealVar x("x", "x", 0., 0.8);

	// read histogram
	TFile* file = new TFile("test.root");
	TH1F* roothist1 = (TH1F*)file->Get("h1");
	// Reading histogram from existing TH1
	RooDataHist* hist = new RooDataHist("Rfit:x", "test", x, (TH1F*)roothist1);
	RooPlot* frame = x.frame(Name("xframe"), Title("test"));

	// peak
	RooRealVar mean("mean", "mean", 0.25, 0.30);
	RooRealVar sigma("sigma", "sigma", 0.15, 0.20);
	RooGaussian gauss("gauss", "gauss", x, mean, sigma);

	//computon
	RooRealVar hn("hn", "hn", 0.662);//ev
	RooRealVar re("re", "re", 0.00000000000000281794);
	RooRealVar me("me", "me", 0.511);//ev 
	RooFormulaVar s("s", "@0/0.662", RooArgList(x));
	RooFormulaVar ga("ga", "@0/@1", RooArgList(hn, me));

	//my idea1 1 or 2
	//TF1* f = new TF1("f", "1/[2]/[2]*([0] *( ([1]*[1])/(([2]*[2])*(1-[1])*(1-[1])) + [1]/(1-[1])*([1]-2/[2]) + 2)", 0, 0.8);
	//RooAbsReal* pdf = RooFit::bindFunction("pdf", f, x, me, s, ga);
	
	//my idea2
	RooGenericPdf pdf("function", "function", "1/@2/@2*(@0 *( (@1*@1)/((@2*@2)*(1-@1)*(1-@1)) + @1/(1-@1)*(@1-2/@2) + 2))", RooArgList(me, s, ga));

	RooNumConvPdf fff("model", "model", x, pdf, gauss);

	x.setBins(100);

	gauss.fitTo(*hist);
	pdf.fitTo(*hist);
	fff.fitTo(*hist);

	hist->plotOn(frame, DrawOption("B"), DataError(RooAbsData::None), XErrorSize(0), FillColor(kBlue));

	gauss.plotOn(frame, Range(0.05, 0.8), LineColor(kMagenta));
	pdf.plotOn(frame, Range(0.05, 0.8), LineColor(kBlack));
	fff.plotOn(frame, Range(0.05, 0.8), LineColor(kYellow));

	frame->GetYaxis()->SetTitleOffset(1.6);
	frame->Draw();

}