df000_simple.C File Reference

Detailed Description

Simple RDataFrame example in C++.

This tutorial shows a minimal example of RDataFrame. It starts without input data, generates a new column x with random numbers, and finally draws a histogram for x.

 
void df000_simple()
{
   // Create a data frame with 100 rows
   ROOT::RDataFrame rdf(100);
 
   // Define a new column `x` that contains random numbers
   auto rdf_x = rdf.Define("x", [](){ return gRandom->Rndm(); });
 
   // Create a histogram from `x`
   auto h = rdf_x.Histo1D("x");
 
   // At the end of this function, the histogram pointed to by `h` will be deleted.
   // Draw a copy of the histogram object instead:
   h->DrawClone();
}

Date

September 2021

Author

Enric Tejedor (CERN)

Definition in file df000_simple.C.