tmva002_RDataFrameAsTensor.C File Reference

Detailed Description

This tutorial shows how the content of an RDataFrame can be converted to an RTensor object.

 
using namespace TMVA::Experimental;
 
void tmva002_RDataFrameAsTensor()
{
   // Creation of an RDataFrame with five entries filled with ascending numbers
   ROOT::RDataFrame df(5);
   auto df2 = df.Define("x", "1.f*rdfentry_").Define("y", "-1.f*rdfentry_");
 
   // Convert content of columns to an RTensor object
   auto x = AsTensor<float>(df2);
 
   std::cout << "RTensor from an RDataFrame:\n" << x << "\n\n";
 
   // The utility also supports reading only a part of the RDataFrame and different
   // memory layouts.
   auto x2 = AsTensor<float>(df2, {"x"}, MemoryLayout::ColumnMajor);
 
   std::cout << "RTensor from a single column of the RDataFrame:\n" << x2 << "\n\n";
}

RTensor from an RDataFrame:
{ { 0, -0 } { 1, -1 } { 2, -2 } { 3, -3 } { 4, -4 } }
 
RTensor from a single column of the RDataFrame:
{ { 0 } { 1 } { 2 } { 3 } { 4 } }
 

Date

December 2018

Author

Stefan Wunsch

Definition in file tmva002_RDataFrameAsTensor.C.