{ "cells": [ { "cell_type": "markdown", "id": "7416ec8e", "metadata": {}, "source": [ "# df033_Describe\n", "Get information about the dataframe with the convenience method Describe.\n", "\n", "\n", "\n", "\n", "**Author:** Stefan Wunsch (KIT, CERN) \n", "This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Tuesday, May 19, 2026 at 08:10 PM." ] }, { "cell_type": "code", "execution_count": 1, "id": "a75e768a", "metadata": { "collapsed": false, "execution": { "iopub.execute_input": "2026-05-19T20:10:10.864041Z", "iopub.status.busy": "2026-05-19T20:10:10.863909Z", "iopub.status.idle": "2026-05-19T20:10:11.871053Z", "shell.execute_reply": "2026-05-19T20:10:11.866455Z" } }, "outputs": [], "source": [ "import ROOT" ] }, { "cell_type": "markdown", "id": "815045e4", "metadata": {}, "source": [ "Create a dataframe" ] }, { "cell_type": "code", "execution_count": 2, "id": "0148a0e0", "metadata": { "collapsed": false, "execution": { "iopub.execute_input": "2026-05-19T20:10:11.883946Z", "iopub.status.busy": "2026-05-19T20:10:11.883802Z", "iopub.status.idle": "2026-05-19T20:10:12.511991Z", "shell.execute_reply": "2026-05-19T20:10:12.511505Z" } }, "outputs": [], "source": [ "path = 'root://eospublic.cern.ch//eos/opendata/cms/derived-data/AOD2NanoAODOutreachTool/Run2012BC_DoubleMuParked_Muons.root'\n", "df = ROOT.RDataFrame('Events', path)" ] }, { "cell_type": "markdown", "id": "2c94fc6f", "metadata": {}, "source": [ "Describe the state of the dataframe.\n", "Note that this operation is not running the event loop.\n", "Describe returns a DFDescription object, which has e.g. a Print method. See its docs for more information." ] }, { "cell_type": "code", "execution_count": 3, "id": "ec38407d", "metadata": { "collapsed": false, "execution": { "iopub.execute_input": "2026-05-19T20:10:12.524346Z", "iopub.status.busy": "2026-05-19T20:10:12.524203Z", "iopub.status.idle": "2026-05-19T20:10:12.642299Z", "shell.execute_reply": "2026-05-19T20:10:12.641918Z" } }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Dataframe from TChain Events in file root://eospublic.cern.ch//eos/opendata/cms/derived-data/AOD2NanoAODOutreachTool/Run2012BC_DoubleMuParked_Muons.root\n", "\n", "Property Value\n", "-------- -----\n", "Columns in total 6\n", "Columns from defines 0\n", "Event loops run 0\n", "Processing slots 1\n", "\n", "Column Type Origin\n", "------ ---- ------\n", "Muon_charge ROOT::VecOps::RVec Dataset\n", "Muon_eta ROOT::VecOps::RVec Dataset\n", "Muon_mass ROOT::VecOps::RVec Dataset\n", "Muon_phi ROOT::VecOps::RVec Dataset\n", "Muon_pt ROOT::VecOps::RVec Dataset\n", "nMuon UInt_t Dataset\n" ] } ], "source": [ "df.Describe().Print()" ] }, { "cell_type": "markdown", "id": "2a5233ee", "metadata": {}, "source": [ "Build a small analysis studying the invariant mass of dimuon systems.\n", "See tutorial df102_NanoAODDimuonAnalysis for more information." ] }, { "cell_type": "code", "execution_count": 4, "id": "9e04c364", "metadata": { "collapsed": false, "execution": { "iopub.execute_input": "2026-05-19T20:10:12.665261Z", "iopub.status.busy": "2026-05-19T20:10:12.665070Z", "iopub.status.idle": "2026-05-19T20:10:13.147704Z", "shell.execute_reply": "2026-05-19T20:10:13.147259Z" } }, "outputs": [], "source": [ "df = df.Filter('nMuon == 2')\\\n", " .Filter('Muon_charge[0] != Muon_charge[1]')\\\n", " .Define('Dimuon_mass', 'InvariantMass(Muon_pt, Muon_eta, Muon_phi, Muon_mass)')\\\n", " .Filter('Dimuon_mass > 70')\\\n", " .Range(1000)" ] }, { "cell_type": "markdown", "id": "b98f289a", "metadata": {}, "source": [ "Trigger the event loop by asking for the mean of the dimuon mass." ] }, { "cell_type": "code", "execution_count": 5, "id": "8208348f", "metadata": { "collapsed": false, "execution": { "iopub.execute_input": "2026-05-19T20:10:13.157218Z", "iopub.status.busy": "2026-05-19T20:10:13.157081Z", "iopub.status.idle": "2026-05-19T20:10:14.654286Z", "shell.execute_reply": "2026-05-19T20:10:14.653834Z" } }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", "Approximate mass of the Z boson: 91.44 GeV\n", "\n" ] } ], "source": [ "print('\\nApproximate mass of the Z boson: {:.2f} GeV\\n'.format(\n", " df.Mean('Dimuon_mass').GetValue()))" ] }, { "cell_type": "markdown", "id": "df010aea", "metadata": {}, "source": [ "This time we ask for the `shortFormat`, which only prints a brief description of the dataset:" ] }, { "cell_type": "code", "execution_count": 6, "id": "e7dfd4d2", "metadata": { "collapsed": false, "execution": { "iopub.execute_input": "2026-05-19T20:10:14.670377Z", "iopub.status.busy": "2026-05-19T20:10:14.670224Z", "iopub.status.idle": "2026-05-19T20:10:14.774285Z", "shell.execute_reply": "2026-05-19T20:10:14.773722Z" } }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Dataframe from TChain Events in file root://eospublic.cern.ch//eos/opendata/cms/derived-data/AOD2NanoAODOutreachTool/Run2012BC_DoubleMuParked_Muons.root" ] } ], "source": [ "df.Describe().Print(shortFormat=True)" ] }, { "cell_type": "markdown", "id": "45d87724", "metadata": {}, "source": [ "Draw all canvases " ] }, { "cell_type": "code", "execution_count": 7, "id": "d2ba4ebf", "metadata": { "collapsed": false, "execution": { "iopub.execute_input": "2026-05-19T20:10:14.775899Z", "iopub.status.busy": "2026-05-19T20:10:14.775747Z", "iopub.status.idle": "2026-05-19T20:10:14.893159Z", "shell.execute_reply": "2026-05-19T20:10:14.892489Z" } }, "outputs": [], "source": [ "from ROOT import gROOT \n", "gROOT.GetListOfCanvases().Draw()" ] } ], "metadata": { "kernelspec": { "display_name": "Python 3", "language": "python", "name": "python3" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.12.12" } }, "nbformat": 4, "nbformat_minor": 5 }