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tutorials
dataframe
tdf008_createDataSetFromScratch.C
Go to the documentation of this file.
1
/// \file
2
/// \ingroup tutorial_tdataframe
3
/// \notebook -nodraw
4
/// This tutorial shows how to create a dataset from scratch with TDataFrame
5
/// \macro_code
6
///
7
/// \date June 2017
8
/// \author Danilo Piparo
9
10
void
tdf008_createDataSetFromScratch
()
11
{
12
// We create an empty data frame of 100 entries
13
ROOT::Experimental::TDataFrame
tdf(100);
14
15
// We now fill it with random numbers
16
gRandom
->
SetSeed
(1);
17
auto
tdf_1 = tdf.Define(
"rnd"
, []() {
return
gRandom
->
Gaus
(); });
18
19
// And we write out the dataset on disk
20
tdf_1.Snapshot(
"randomNumbers"
,
"tdf008_createDataSetFromScratch.root"
);
21
}
TRandom::Gaus
virtual Double_t Gaus(Double_t mean=0, Double_t sigma=1)
Samples a random number from the standard Normal (Gaussian) Distribution with the given mean and sigm...
Definition:
TRandom.cxx:256
TRandom::SetSeed
virtual void SetSeed(ULong_t seed=0)
Set the random generator seed.
Definition:
TRandom.cxx:589
gRandom
R__EXTERN TRandom * gRandom
Definition:
TRandom.h:62
tdf008_createDataSetFromScratch
Definition:
tdf008_createDataSetFromScratch.py:1
ROOT::Experimental::TDataFrame
ROOT's TDataFrame offers a high level interface for analyses of data stored in TTrees.
Definition:
TDataFrame.hxx:39