using namespace RooFit;

void stack_test()
{
	RooRealVar var("var","var",2,4,"dim");

	RooRealVar sig_mean("sig_mean","mean",3,2.9,3.1"dim");
	RooRealVar sig_res("si_res","res",.1,.05,.2,"dim");
	RooGaussian sig_pdf("sig_pdf","Signal",var,sig_mean,sig_res);

	RooRealVar bkg1_shape("bkg1_shape","shape1",-2,-.5,-10,"1/dim");
	RooExponential bkg1_pdf("bkg1_pdf","Bkg 1",var,bkg1_shape);

	RooUniform bkg2_pdf("bkg2_pdf","Bkg 2",var);

	RooRealVar Fsgn("Fsgn","Signal fraction",.3,.2,.4);
	RooRealVar Fbkg1("Fbkg1","Frac Bkg 1",.4,.2,.6);
	RooAddPdf tot_pdf("tot_pdf","Global shape",RooArgList(sig_pdf,bkg1_pdf,bkg2_pdf),RooArgList(Fsgn,Fbkg1));

	RooAbsData *data = tot_pdf.generate(var,2000);
	//tot_pdf.fitTo(*data);

	TCanvas *canvas_comps = new TCanvas("canvas_comps","Components",1);
	RooPlot *frame = var.frame(Title("Test"),Name("frame"));
	data->plotOn(frame,Name("data"),Binning(30));
	tot_pdf.plotOn(frame,Name("signal"),LineColor(kBlue),LineStyle(2),Components("sig_pdf"));
	tot_pdf.plotOn(frame,Name("Bkg1"),LineColor(kViolet),LineStyle(2),Components("bkg1_pdf"));
	tot_pdf.plotOn(frame,Name("Bkg2"),LineColor(kYellow),LineStyle(2),Components("bkg2_pdf"));
	tot_pdf.plotOn(frame,Name("total"),LineColor(kRed));
	frame->Draw();

	TCanvas *canvas_stack = new TCanvas("canvas_stack","Stack",1);
	RooPlot *frame_stacked = var.frame(Title("Test"),Name("frame_stacked"));
	data->plotOn(frame_stacked,Name("dataS"),Binning(30));
	tot_pdf.plotOn(frame_stacked,Name("Bkg2S"),LineColor(kYellow),LineStyle(2),Components("bkg2_pdf"));
	tot_pdf.plotOn(frame_stacked,Name("Bkg1S"),LineColor(kViolet),LineStyle(2),Components("bkg1_pdf"),AddTo("Bkg2S",0));
	tot_pdf.plotOn(frame_stacked,AddTo("Bkg1S"),Name("signal"),LineColor(kBlue),LineStyle(2),Components("sig_pdf"));
	tot_pdf.plotOn(frame_stacked,Name("totalS"),LineColor(kRed));
	frame->Draw();

}