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tmva103_Application.C File Reference

Detailed Description

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This tutorial illustrates how you can conveniently apply BDTs in C++ using the fast tree inference engine offered by TMVA.

Supported workflows are event-by-event inference, batch inference and pipelines with RDataFrame.

using namespace TMVA::Experimental;
void tmva103_Application()
const char* model_filename = "tmva101.root";
if (gSystem->AccessPathName(model_filename)) {
Info("tmva103_Application.C", "%s does not exist", model_filename);
// Load BDT model
RBDT bdt("myBDT", model_filename);
// Apply model on a single input
auto y1 = bdt.Compute({1.0, 2.0, 3.0, 4.0});
std::cout << "Apply model on a single input vector: " << y1[0] << std::endl;
// Apply model on a batch of inputs
float data[8] = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0};
RTensor<float> x(data, {2, 4});
auto y2 = bdt.Compute(x);
std::cout << "Apply model on an input tensor: " << y2 << std::endl;
// Apply model as part of an RDataFrame workflow
ROOT::RDataFrame df("Events", "root://eospublic.cern.ch//eos/root-eos/cms_opendata_2012_nanoaod/SMHiggsToZZTo4L.root");
auto df2 = df.Filter("nMuon >= 2")
.Filter("nElectron >= 2")
.Define("Muon_pt_1", "Muon_pt[0]")
.Define("Muon_pt_2", "Muon_pt[1]")
.Define("Electron_pt_1", "Electron_pt[0]")
.Define("Electron_pt_2", "Electron_pt[1]")
Compute<4, float>(bdt),
{"Muon_pt_1", "Muon_pt_2", "Electron_pt_1", "Electron_pt_2"});
std::cout << "Mean response on the signal sample: " << *df2.Mean("y") << std::endl;
void Info(const char *location, const char *msgfmt,...)
Use this function for informational messages.
Definition TError.cxx:218
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void data
Option_t Option_t TPoint TPoint const char y2
Option_t Option_t TPoint TPoint const char y1
R__EXTERN TSystem * gSystem
Definition TSystem.h:555
ROOT's RDataFrame offers a modern, high-level interface for analysis of data stored in TTree ,...
RTensor is a container with contiguous memory and shape information.
Definition RTensor.hxx:162
virtual Bool_t AccessPathName(const char *path, EAccessMode mode=kFileExists)
Returns FALSE if one can access a file using the specified access mode.
Definition TSystem.cxx:1296
Double_t x[n]
Definition legend1.C:17
December 2018
Stefan Wunsch

Definition in file tmva103_Application.C.