Roofit

I’m trying plot a variable from a root file but it’s getting error. Roofit says that it has no entries.

#ifndef __CINT__
#include "RooGlobalFunc.h"
#endif
#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooDataHist.h"
#include "RooGaussian.h"
#include "TCanvas.h"
#include "RooPlot.h"
#include "TTree.h"
#include "TH1D.h"
#include "TRandom.h"
using namespace RooFit ;

void D_MMimport()
{

// Import TTree
TFile *file = new TFile("KKK_MagUp.root");
TTree* tree = (TTree*)file->Get("DecayTree/D_MM");

  // Declare observable x
  RooRealVar D_MM("D_MM","D_MM",1920,2020) ;

  // Create a binned dataset that imports contents of TH1 and associates its contents to observable 'x'
  RooDataSet dh("dh","dh",RooArgSet(D_MM),Import(*tree)) ;

  

  RooPlot* frame = D_MM.frame(Title("Ds"));

  dh.plotOn(frame,Binning(100));

  dh.ls();

 frame->Draw();

}




Hi,

could you share the input file too in order to make the script reproducible?

Cheers,
Danilo