Tree tutorials

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

Files
file	basic.C
	Read data from an ascii file and create a root file with an histogram and an ntuple.
file	basic2.C
	Create can ntuple reading data from an ascii file.
file	bill.C
	Benchmark comparing row-wise and column-wise storage performance
file	cernbuild.C
	Read data (CERN staff) from an ascii file and create a root file with a Tree.
file	cernstaff.C
	Playing with a Tree containing variables of type character
file	circular.C
	Example of a circular Tree
file	clonesA_Event.C
	Example to write & read a Tree built with a complex class inheritance tree.
file	copytree.C
	Copy a subset of a Tree to a new Tree
file	copytree2.C
	Copy a subset of a Tree to a new Tree, one branch in a separate file.
file	copytree3.C
	Example of Root macro to copy a subset of a Tree to a new Tree, selecting entries.
file	drawsparse.C
	Convert a THnSparse to a TTree using efficient iteration through the THnSparse and draw a THnSparse using TParallelCoord.
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	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
file	hsimpleProxyDriver.C
	This is the driver of the hsimpleProxy example It provides the infrastructure to run that code on an ntuple To be run from the tutorials directory
file	hsimpleReader.C
	TTreeReader simplest example.
file	htest.C
	Save histograms in Tree branches
file	hvector.C
	Write and read STL vectors in a tree.
file	jets.C
	Usage of a Tree using the JetEvent class.
file	ntuple1.C
	Simple tree analysis.
file	parallelcoord.C
	Script illustrating the use of the TParalleCoord class
file	parallelcoordtrans.C
	Use of transparency with ||-Coord.
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	spider.C
	TSpider example.
file	staff.C
	Create a plot of the data in cernstaff.root To create cernstaff.root, execute tutorial $ROOTSYS/tutorials/tree/cernbuild.C
file	tcl.C
	How to write a TClonesArray to a TTree
file	tree.C
	Display the Tree data structures
file	tree0.C
	Simple Event class example
file	tree1.C
	This example is a variant of hsimple.C but using a TTree instead of a TNtuple.
file	tree2.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	tree2a.C
	This example is the same as tree2.C, but uses a class instead of a C-struct.
file	tree3.C
	Example of a Tree where branches are variable length arrays A second Tree is created and filled in parallel.
file	tree4.C
	This example writes a tree with objects of the class Event.
file	treefriend.C
	Illustrates how to use Tree friends:
file	treegetval.C
	Illustrates how to retrieve TTree variables in arrays.