Get information about the dataframe with the convenience method Describe.
Author: Stefan Wunsch (KIT, CERN)
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Wednesday, April 17, 2024 at 11:07 AM.
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)
Plugin No such file or directory loading sec.protocol libXrdSeckrb5-5.so
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.
df.Describe().Print()
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 Processing slots 1 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
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')\
.Range(1000)
Trigger the event loop by asking for the mean of the dimuon mass.
print('\nApproximate mass of the Z boson: {:.2f} GeV\n'.format(
df.Mean('Dimuon_mass').GetValue()))
Approximate mass of the Z boson: 91.44 GeV
This time we ask for the shortFormat
, which only prints a brief description of the dataset:
df.Describe().Print(shortFormat=True)
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 7 Columns from defines 1 Event loops run 1 Processing slots 1 Column Type Origin ------ ---- ------ Dimuon_mass float Define 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
Draw all canvases
from ROOT import gROOT
gROOT.GetListOfCanvases().Draw()