Logo ROOT  
Reference Guide
ntpl004_dimuon.C File Reference

Detailed Description

View in nbviewer Open in SWAN
Mini-Analysis on CMS OpenData with RDataFrame.

This tutorial illustrates that analyzing data with RDataFrame works the same for both TTree data and RNTuple data. The RNTuple data are converted from the Events tree in http://root.cern.ch/files/NanoAOD_DoubleMuon_CMS2011OpenData.root Based on RDataFrame's df102_NanoAODDimuonAnalysis.C

// NOTE: The RNTuple classes are experimental at this point.
// Functionality, interface, and data format is still subject to changes.
// Do not use for real data!
// Until C++ runtime modules are universally used, we explicitly load the ntuple library. Otherwise
// triggering autoloading from the use of templated types would require an exhaustive enumeration
// of "all" template instances in the LinkDef file.
#include <ROOT/RDataFrame.hxx>
#include <ROOT/RNTuple.hxx>
#include <ROOT/RVec.hxx>
#include <TCanvas.h>
#include <TH1D.h>
#include <TLatex.h>
#include <TStyle.h>
#include <cassert>
#include <cmath>
#include <iostream>
#include <memory>
#include <string>
#include <vector>
#include <utility>
// Import classes from experimental namespace for the time being
using RNTupleReader = ROOT::Experimental::RNTupleReader;
constexpr char const* kNTupleFileName = "http://root.cern.ch/files/tutorials/ntpl004_dimuon_v1rc1.root";
using namespace ROOT::VecOps;
void ntpl004_dimuon() {
// Use all available CPU cores
auto df = ROOT::RDF::Experimental::FromRNTuple("Events", kNTupleFileName);
// The tutorial is identical to df102_NanoAODDimuonAnalysis except the use of
// InvariantMassStdVector instead of InvariantMass (to be fixed in a later version of RNTuple)
// For simplicity, select only events with exactly two muons and require opposite charge
auto df_2mu = df.Filter("#Muon == 2", "Events with exactly two muons");
auto df_os = df_2mu.Filter("Muon.charge[0] != Muon.charge[1]", "Muons with opposite charge");
// Compute invariant mass of the dimuon system
auto df_mass = df_os.Define("Dimuon_mass", InvariantMass<float>, {"Muon.pt", "Muon.eta", "Muon.phi", "Muon.mass"});
// Make histogram of dimuon mass spectrum
auto h = df_mass.Histo1D({"Dimuon_mass", "Dimuon_mass", 30000, 0.25, 300}, "Dimuon_mass");
// Request cut-flow report
auto report = df_mass.Report();
// Produce plot
auto c = new TCanvas("c", "", 800, 700);
c->SetLogx(); c->SetLogy();
h->GetXaxis()->SetTitle("m_{#mu#mu} (GeV)"); h->GetXaxis()->SetTitleSize(0.04);
h->GetYaxis()->SetTitle("N_{Events}"); h->GetYaxis()->SetTitleSize(0.04);
TLatex label; label.SetNDC(true);
label.DrawLatex(0.175, 0.740, "#eta");
label.DrawLatex(0.205, 0.775, "#rho,#omega");
label.DrawLatex(0.270, 0.740, "#phi");
label.DrawLatex(0.400, 0.800, "J/#psi");
label.DrawLatex(0.415, 0.670, "#psi'");
label.DrawLatex(0.485, 0.700, "Y(1,2,3S)");
label.DrawLatex(0.755, 0.680, "Z");
label.SetTextSize(0.040); label.DrawLatex(0.100, 0.920, "#bf{CMS Open Data}");
label.SetTextSize(0.030); label.DrawLatex(0.630, 0.920, "#sqrt{s} = 8 TeV, L_{int} = 11.6 fb^{-1}");
// Print cut-flow report
#define c(i)
Definition: RSha256.hxx:101
#define h(i)
Definition: RSha256.hxx:106
Definition: Rtypes.h:489
R__EXTERN TStyle * gStyle
Definition: TStyle.h:414
The RDataSource implementation for RNTuple.
Definition: RNTupleDS.hxx:46
An RNTuple that is used to read data from storage.
Definition: RNTuple.hxx:110
virtual void SetTextFont(Font_t tfont=62)
Set the text font.
Definition: TAttText.h:46
virtual void SetTextSize(Float_t tsize=1)
Set the text size.
Definition: TAttText.h:47
The Canvas class.
Definition: TCanvas.h:23
Definition: TLatex.h:18
TLatex * DrawLatex(Double_t x, Double_t y, const char *text)
void SetOptStat(Int_t stat=1)
The type of information printed in the histogram statistics box can be selected via the parameter mod...
Definition: TStyle.cxx:1589
virtual void SetNDC(Bool_t isNDC=kTRUE)
void Print(Option_t *option="") const override
Print TNamed name and title.
RDataFrame FromRNTuple(std::string_view ntupleName, std::string_view fileName)
Definition: RNTupleDS.cxx:359
void EnableImplicitMT(UInt_t numthreads=0)
Enable ROOT's implicit multi-threading for all objects and methods that provide an internal paralleli...
Definition: TROOT.cxx:527
April 2019
The ROOT Team

Definition in file ntpl004_dimuon.C.