Tree tutorials

Example code which illustrates how to use ROOT trees and ntuples.

Files
file	csv2tntuple.py
	Build ROOT Ntuple from other source.
file	csv2tree_ReadStream.py
	This function provides an example of how one might massage a csv data file to read into a ROOT TTree via TTree::ReadStream.
file	h1analysis.C
	Example of analysis class for the H1 data.
file	h1analysisProxy.C
	Example of analysis class for the H1 data using code generated by MakeProxy.
file	h1analysisTreeReader.C
	H1 analysis example expressed in terms of TTreeReader (see h1analysis.C).
file	h1chain.C
	Creates a TChain to be used by the h1analysis.C class the symbol H1 must point to a directory where the H1 data sets have been installed.
file	hsimpleProxy.C
	Used by hsimpleProxyDriver.C.
file	hsimpleProxyDriver.C
	This is the driver of the hsimpleProxy example.
file	hsimpleReader.C
	TTreeReader simplest example.
file	imt_parBranchProcessing.C
	Demonstrate how to activate and use the implicit parallelisation of TTree::GetEntry.
file	imt_parTreeProcessing.C
	Illustrate the usage of the TTreeProcessorMT::Process method.
file	mp_fillNtuples.C
	Fill n-tuples in distinct workers.
file	mp_readNtuplesFillHistosAndFit.C
	Read n-tuples in distinct workers, fill histograms, merge them and fit.
file	mt_fillNtupleFromMultipleThreads.C
	Fill the same TNtuple from different threads.
file	mt_fillNtuples.C
	Fill n-tuples in distinct workers.
file	mt_readNtuplesFillHistosAndFit.C
	Read n-tuples in distinct workers, fill histograms, merge them and fit.
file	mtbb_fillNtuples.C
	Fill n-tuples in distinct workers.
file	ntuple1.py
	Ntuple drawing example.
file	printSizes.C
	This macro can be used to get aggregate information on the size take on disk or in memory by the various branches in a TTree.
file	run_h1analysis.C
	Macro driving the analysis can specify file name and type
file	staff.py
	example of macro to read data from an ascii file and create a root file with a Tree.
file	tree.C
	Display the Tree data structures
file	tree101_basic.C
	Read data from an ascii file and create a root file with an histogram and an ntuple.
file	tree102_basic.C
	Create can ntuple reading data from an ascii file.
file	tree103_tree.C
	Simple Event class example
file	tree104_tree.C
	This example is a variant of hsimple.C but using a TTree instead of a TNtuple.
file	tree105_tree.C
	This example illustrates how to make a Tree from variables or arrays in a C struct - without a dictionary, by creating the branches for builtin types (int, float, double) and arrays explicitly.
file	tree106_tree.C
	This example is the same as tree105_tree.C, but uses a class instead of a C-struct.
file	tree107_tree.C
	Example of a Tree where branches are variable length arrays A second Tree is created and filled in parallel.
file	tree108_tree.C
	This example writes a tree with objects of the class Event.
file	tree109_friend.C
	Illustrates how to use Tree friends:
file	tree110_copy.C
	Copy a subset of a Tree to a new Tree
file	tree111_copy.C
	Copy a subset of a Tree to a new Tree, one branch in a separate file.
file	tree112_copy.C
	Example of Root macro to copy a subset of a Tree to a new Tree, selecting entries.
file	tree113_getval.C
	Illustrates how to retrieve TTree variables in arrays.
file	tree114_circular.C
	Example of a circular Tree
file	tree120_ntuple.C
	Simple tree analysis.
file	tree121_hvector.C
	Write and read STL vectors in a tree.
file	tree122_vector3.C
	Write and read a Vector3 class in a tree.
file	tree123_clonesarray.C
	How to write a TClonesArray to a TTree
file	tree130_jets.C
	Usage of a Tree using the JetEvent class.
file	tree131_clones_event.C
	Example to write & read a Tree built with a complex class inheritance tree.
file	tree140_spider.C
	TSpider example.
file	tree141_parallelcoord.C
	Script illustrating the use of the TParallelCoord class
file	tree142_parallelcoordtrans.C
	Use of transparency with ||-Coord.
file	tree143_drawsparse.C
	Convert a THnSparse to a TTree using efficient iteration through the THnSparse and draw a THnSparse using TParallelCoord.
file	tree200_temperature.C
	This tutorial illustrates how to use the highlight mode with trees.
file	tree201_histograms.C
	Save histograms in Tree branches
file	tree202_benchmarks.C
	Benchmark comparing row-wise and column-wise storage performance
file	tree500_cernbuild.C
	Read data (CERN staff) from an ascii file and create a root file with a Tree.
file	tree501_cernstaff.C
	Playing with a Tree containing variables of type character
file	tree502_staff.C
	Create a plot of the data in cernstaff.root To create cernstaff.root, execute tutorial $ROOTSYS/tutorials/io/tree/tree500_cernbuild.C