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mrt.py File Reference

Namespaces

namespace  mrt
 

Detailed Description

View in nbviewer Open in SWAN Build ROOT Ntuple from other source.

This program reads the ‘aptuple.txt’ file row by row, then creates the Ntuple by adding row by row.

import sys, os
from ROOT import TFile, TNtuple, TROOT
ifn = os.path.join(str(TROOT.GetTutorialDir()), 'pyroot', 'aptuple.txt')
ofn = 'aptuple.root'
print('opening file %s ...' % ifn)
infile = open( ifn, 'r' )
lines = infile.readlines()
title = lines[0]
labels = lines[1].split()
print('writing file %s ...' % ofn)
outfile = TFile( ofn, 'RECREATE', 'ROOT file with an NTuple' )
ntuple = TNtuple( 'ntuple', title, ':'.join( labels ) )
for line in lines[2:]:
words = line.split()
row = map( float, words )
ntuple.Fill(*row)
outfile.Write()
print('done')
A ROOT file is a suite of consecutive data records (TKey instances) with a well defined format.
Definition TFile.h:54
A simple TTree restricted to a list of float variables only.
Definition TNtuple.h:28
static const TString & GetTutorialDir()
Get the tutorials directory in the installation. Static utility function.
Definition TROOT.cxx:3032
Author
Wim Lavrijsen

Definition in file mrt.py.