How to use unbin fit if I use .generate to create data?

Roofit and RooStats
1

Hello!

I want use unbin fit to get parameters.
How to do this if I created data via .generate ?

void RooFit_my()
{
	RooRealVar t("t","time", 0, 250);
	RooRealVar tau("tau","tau parameter", 50, 1, 100);
	RooGenericPdf genpdf("genpdf","genpdf","( 1 / tau * exp( - t / tau ) )", RooArgSet(t, tau));
	RooDataSet* data = genpdf.generate(t, 500);
	genpdf.fitTo(*data);
	tau.Print();
	
	RooPlot* tframe = t.frame(Title("Interpreted expression pdf"));
	data->plotOn(tframe);
	genpdf.plotOn(tframe);
	
	TCanvas* c = new TCanvas("rf103_interprfuncs","rf103_interprfuncs",800,400);
	tframe->GetYaxis()->SetTitleOffset(1.4);
	tframe->Draw();
}

Yours respectfully, Vladislav.

2

Hi,

The data you have generated are already un-binned, and therefore the fit you are doing afterwards is also unbinned.
You would have to call generateBinned to get a binned data set (as a RooDatahist object)

Best Regards

Lorenzo

3

Thanks a lot!
I am much obliged to you for your help!