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df033_Describe.py File Reference


namespace  df033_Describe

Detailed Description

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Get information about the dataframe with the convenience method Describe.

import ROOT
# Create a dataframe
path = 'root://eospublic.cern.ch//eos/opendata/cms/derived-data/AOD2NanoAODOutreachTool/Run2012BC_DoubleMuParked_Muons.root'
df = ROOT.RDataFrame('Events', path)
# Describe the state of the dataframe.
# Note that this operation is not running the event loop.
# Describe returns a DFDescription object, which has e.g. a Print method. See its docs for more information.
# Build a small analysis studying the invariant mass of dimuon systems.
# See tutorial df102_NanoAODDimuonAnalysis for more information.
df = df.Filter('nMuon == 2')\
.Filter('Muon_charge[0] != Muon_charge[1]')\
.Define('Dimuon_mass', 'InvariantMass(Muon_pt, Muon_eta, Muon_phi, Muon_mass)')\
.Filter('Dimuon_mass > 70')\
# Trigger the event loop by asking for the mean of the dimuon mass.
print('\nApproximate mass of the Z boson: {:.2f} GeV\n'.format(
# This time we ask for the `shortFormat`, which only prints a brief description of the dataset:
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void char Point_t Rectangle_t WindowAttributes_t Float_t Float_t Float_t Int_t Int_t UInt_t UInt_t Rectangle_t Int_t Int_t Window_t TString Int_t GCValues_t GetPrimarySelectionOwner GetDisplay GetScreen GetColormap GetNativeEvent const char const char dpyName wid window const char font_name cursor keysym reg const char only_if_exist regb h Point_t winding char text const char depth char const char Int_t count const char ColorStruct_t color const char Pixmap_t Pixmap_t PictureAttributes_t attr const char char ret_data h unsigned char height h Atom_t Int_t ULong_t ULong_t unsigned char prop_list Atom_t Atom_t Atom_t Time_t format
ROOT's RDataFrame offers a modern, high-level interface for analysis of data stored in TTree ,...
Ta Range(0, 0, 1, 1)
Dataframe from TChain Events in file root://eospublic.cern.ch//eos/opendata/cms/derived-data/AOD2NanoAODOutreachTool/Run2012BC_DoubleMuParked_Muons.root
Property Value
-------- -----
Columns in total 6
Columns from defines 0
Event loops run 0
Column Type Origin
------ ---- ------
Muon_charge ROOT::VecOps::RVec<Int_t> Dataset
Muon_eta ROOT::VecOps::RVec<Float_t> Dataset
Muon_mass ROOT::VecOps::RVec<Float_t> Dataset
Muon_phi ROOT::VecOps::RVec<Float_t> Dataset
Muon_pt ROOT::VecOps::RVec<Float_t> Dataset
nMuon UInt_t Dataset
Approximate mass of the Z boson: 91.44 GeV
Dataframe from TChain Events in file root://eospublic.cern.ch//eos/opendata/cms/derived-data/AOD2NanoAODOutreachTool/Run2012BC_DoubleMuParked_Muons.root
March 2021
Stefan Wunsch (KIT, CERN)

Definition in file df033_Describe.py.