using namespace RooFit;

void minimal_example_fit()
{
        // dataset generated with default shape parameters, and normalizations are:
        // ngaus_1 = 10000
        // ngaus_2 = 1000
        // nbkg    = 5000

        TFile* fileIn = new TFile("minimal_output_generated.root","READONLY");
        RooWorkspace* wIn  = (RooWorkspace*) fileIn->Get("w") ;
        RooDataSet *data = (RooDataSet*) wIn->data("data_generated");

	RooRealVar x("x","x",0.,1.);
	
	RooRealVar mean_1("mean_1","mean 1",0.135,0.134,0.136);
	RooRealVar sigma_1("sigma_1","sigma 1",0.006,0.005,0.007);
	RooGaussian gaus_1("gaus_1","gaus 1",x,mean_1,sigma_1);

	RooRealVar mean_2("mean_2","mean 2",0.548,0.547,0.549);
	RooRealVar sigma_2("sigma_2","sigma 2",0.0098,0.0097,0.0099);
	RooGaussian gaus_2("gaus_2","gaus 2",x,mean_2,sigma_2);

	RooRealVar a0("a0","a0",1.,0.,2.);
	RooPolynomial bkg("bkg","bkg",x,RooArgSet(a0));

	RooRealVar ngaus_1("ngaus_1","ngaus 1",8000.,100,100000);
	RooRealVar ngaus_2("ngaus_2","ngaus ",2000.,100,100000);
	RooRealVar nbkg("nbkg","nbkg",8000.,10,10000);

	RooAddPdf model("model","model",RooArgList(gaus_1,gaus_2,bkg),RooArgList(ngaus_1,ngaus_2,nbkg));

        x.setRange("SBLeft", 0., 0.33);
        x.setRange("SBRight", 0.37 , 1.);

	//RooFitResult* result = model.fitTo(*data); // success
	RooFitResult* result = model.fitTo(*data,Range("SBLeft,SBRight")); // fail




	RooPlot* xframe = x.frame(Title("sideband fit example")) ;
	data->plotOn(xframe, Binning(500,0,1)) ;
	model.plotOn(xframe,Normalization(1.0,RooAbsReal::RelativeExpected)) ;

	model.plotOn(xframe,Components(bkg),LineStyle(kDashed),LineColor(kRed),Normalization(1.0,RooAbsReal::RelativeExpected)) ;

	model.Print("t") ;

	TCanvas* canv = new TCanvas("canv","canv",600,600) ;
	gPad->SetLeftMargin(0.15);
	gPad->SetLogy();
	xframe->GetYaxis()->SetTitleOffset(1.4);
	xframe->Draw();

	canv->Print("minimal_output_fit.pdf");
}