A chain is a collection of files containing TTree objects.

When the chain is created, the first parameter is the default name for the Tree to be processed later on.

Enter a new element in the chain via the TChain::Add function. Once a chain is defined, one can use the normal TTree functions to Draw,Scan,etc.

Use TChain::SetBranchStatus to activate one or more branches for all the trees in the chain.

Definition at line 34 of file TChain.h.

Public Types
enum	EStatusBits { kGlobalWeight = BIT(15) , kAutoDelete = BIT(16) , kProofUptodate = BIT(17) , kProofLite = BIT(18) }

Public Types inherited from TTree
enum	{ kSplitCollectionOfPointers = 100 }

enum	ESetBranchAddressStatus { kMissingBranch = -5 , kInternalError = -4 , kMissingCompiledCollectionProxy = -3 , kMismatch = -2 , kClassMismatch = -1 , kMatch = 0 , kMatchConversion = 1 , kMatchConversionCollection = 2 , kMakeClass = 3 , kVoidPtr = 4 , kNoCheck = 5 , kNeedEnableDecomposedObj = BIT(29) , kNeedDisableDecomposedObj = BIT(30) , kDecomposedObjMask = kNeedEnableDecomposedObj \| kNeedDisableDecomposedObj }

enum	EStatusBits { kForceRead = BIT(11) , kCircular = BIT(12) , kOnlyFlushAtCluster = BIT(14) , kEntriesReshuffled = BIT(19) }

Public Types inherited from TObject
enum	{ kIsOnHeap = 0x01000000 , kNotDeleted = 0x02000000 , kZombie = 0x04000000 , kInconsistent = 0x08000000 , kBitMask = 0x00ffffff }

enum	{ kSingleKey = BIT(0) , kOverwrite = BIT(1) , kWriteDelete = BIT(2) }

enum	EDeprecatedStatusBits { kObjInCanvas = BIT(3) }

enum	EStatusBits { kCanDelete = BIT(0) , kMustCleanup = BIT(3) , kIsReferenced = BIT(4) , kHasUUID = BIT(5) , kCannotPick = BIT(6) , kNoContextMenu = BIT(8) , kInvalidObject = BIT(13) }

Public Member Functions
	TChain ()
	Default constructor. More...

	TChain (const char name, const char title="")
	Create a chain. More...

virtual	~TChain ()
	Destructor. More...

virtual Int_t	Add (const char *name, Long64_t nentries=TTree::kMaxEntries)
	Add a new file to this chain. More...

virtual Int_t	Add (TChain *chain)
	Add all files referenced by the passed chain to this chain. More...

virtual Int_t	AddFile (const char name, Long64_t nentries=TTree::kMaxEntries, const char tname="")
	Add a new file to this chain. More...

virtual Int_t	AddFileInfoList (TCollection *list, Long64_t nfiles=TTree::kMaxEntries)
	Add all files referenced in the list to the chain. More...

virtual TFriendElement *	AddFriend (const char chainname, const char dummy="")
	Add a TFriendElement to the list of friends of this chain. More...

virtual TFriendElement *	AddFriend (const char chainname, TFile dummy)
	Add the whole chain or tree as a friend of this chain. More...

virtual TFriendElement *	AddFriend (TTree chain, const char alias="", Bool_t warn=kFALSE)
	Add the whole chain or tree as a friend of this chain. More...

virtual void	Browse (TBrowser *)
	Browse the contents of the chain. More...

virtual void	CanDeleteRefs (Bool_t flag=kTRUE)
	When closing a file during the chain processing, the file may be closed with option "R" if flag is set to kTRUE. More...

virtual void	CreatePackets ()
	Initialize the packet descriptor string. More...

virtual void	DirectoryAutoAdd (TDirectory *)
	Override the TTree::DirectoryAutoAdd behavior: we never auto add. More...

virtual Long64_t	Draw (const char varexp, const char selection, Option_t *option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Process all entries in this chain and draw histogram corresponding to expression varexp. More...

virtual Long64_t	Draw (const char varexp, const TCut &selection, Option_t option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Draw expression varexp for selected entries. More...

virtual void	Draw (Option_t *opt)
	Default Draw method for all objects. More...

virtual Int_t	Fill ()
	Fill all branches. More...

virtual TBranch *	FindBranch (const char *name)
	See TTree::GetReadEntry(). More...

virtual TLeaf *	FindLeaf (const char *name)
	See TTree::GetReadEntry(). More...

virtual const char *	GetAlias (const char *aliasName) const
	Returns the expanded value of the alias. Search in the friends if any. More...

virtual TBranch *	GetBranch (const char *name)
	Return pointer to the branch name in the current tree. More...

virtual Bool_t	GetBranchStatus (const char *branchname) const
	See TTree::GetReadEntry(). More...

virtual Long64_t	GetCacheSize () const

virtual Long64_t	GetChainEntryNumber (Long64_t entry) const
	Return absolute entry number in the chain. More...

virtual TClusterIterator	GetClusterIterator (Long64_t firstentry)
	Return an iterator over the cluster of baskets starting at firstentry. More...

virtual Long64_t	GetEntries () const
	Return the total number of entries in the chain. More...

virtual Long64_t	GetEntries (const char *sel)
	Return the number of entries matching the selection. More...

virtual Int_t	GetEntry (Long64_t entry=0, Int_t getall=0)
	Get entry from the file to memory. More...

virtual Long64_t	GetEntryNumber (Long64_t entry) const
	Return entry number corresponding to entry. More...

virtual Int_t	GetEntryWithIndex (Int_t major, Int_t minor=0)
	Return entry corresponding to major and minor number. More...

TFile *	GetFile () const
	Return a pointer to the current file. More...

virtual TLeaf *	GetLeaf (const char branchname, const char leafname)
	Return a pointer to the leaf name in the current tree. More...

virtual TLeaf *	GetLeaf (const char *name)
	Return a pointer to the leaf name in the current tree. More...

virtual TObjArray *	GetListOfBranches ()
	Return a pointer to the list of branches of the current tree. More...

TObjArray *	GetListOfFiles () const

virtual TObjArray *	GetListOfLeaves ()
	Return a pointer to the list of leaves of the current tree. More...

virtual Double_t	GetMaximum (const char *columname)
	Return maximum of column with name columname. More...

virtual Double_t	GetMinimum (const char *columname)
	Return minimum of column with name columname. More...

virtual Int_t	GetNbranches ()
	Return the number of branches of the current tree. More...

Int_t	GetNtrees () const

virtual Long64_t	GetReadEntry () const
	See TTree::GetReadEntry(). More...

TList *	GetStatus () const

virtual TTree *	GetTree () const

virtual Int_t	GetTreeNumber () const

Long64_t *	GetTreeOffset () const

Int_t	GetTreeOffsetLen () const

virtual Double_t	GetWeight () const
	Return the chain weight. More...

virtual Int_t	LoadBaskets (Long64_t maxmemory)
	Dummy function. More...

virtual Long64_t	LoadTree (Long64_t entry)
	Find the tree which contains entry, and set it as the current tree. More...

void	Lookup (Bool_t force=kFALSE)
	Check / locate the files in the chain. More...

virtual void	Loop (Option_t *option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Loop on nentries of this chain starting at firstentry. (NOT IMPLEMENTED) More...

virtual void	ls (Option_t *option="") const
	List the chain. More...

virtual Long64_t	Merge (const char name, Option_t option="")
	Merge all the entries in the chain into a new tree in a new file. More...

virtual Long64_t	Merge (TCollection list, Option_t option="")
	Merge all chains in the collection. (NOT IMPLEMENTED) More...

virtual Long64_t	Merge (TCollection list, TFileMergeInfo info)
	Merge all chains in the collection. (NOT IMPLEMENTED) More...

virtual Long64_t	Merge (TFile file, Int_t basketsize, Option_t option="")
	Merge all the entries in the chain into a new tree in the current file. More...

virtual void	Print (Option_t *option="") const
	Print the header information of each tree in the chain. More...

virtual Long64_t	Process (const char filename, Option_t option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Process all entries in this chain, calling functions in filename. More...

virtual Long64_t	Process (TSelector selector, Option_t option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Process this chain executing the code in selector. More...

virtual void	RecursiveRemove (TObject *obj)
	Make sure that obj (which is being deleted or will soon be) is no longer referenced by this TTree. More...

virtual void	RemoveFriend (TTree *)
	Remove a friend from the list of friends. More...

virtual void	Reset (Option_t *option="")
	Resets the state of this chain. More...

virtual void	ResetAfterMerge (TFileMergeInfo *)
	Resets the state of this chain after a merge (keep the customization but forget the data). More...

virtual void	ResetBranchAddress (TBranch *)
	Reset the addresses of the branch. More...

virtual void	ResetBranchAddresses ()
	Reset the addresses of the branches. More...

virtual void	SavePrimitive (std::ostream &out, Option_t *option="")
	Save TChain as a C++ statements on output stream out. More...

virtual Long64_t	Scan (const char varexp="", const char selection="", Option_t *option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Loop on tree and print entries passing selection. More...

virtual void	SetAutoDelete (Bool_t autodel=kTRUE)
	Set the global branch kAutoDelete bit. More...

template<class T >
Int_t	SetBranchAddress (const char bname, T add, TBranch *ptr=0)

template<class T >
Int_t	SetBranchAddress (const char bname, T add, TBranch **ptr=0)

virtual Int_t	SetBranchAddress (const char bname, void add, TBranch *ptr, TClass realClass, EDataType datatype, Bool_t isptr)
	Check if bname is already in the status list, and if not, create a TChainElement object and set its address. More...

virtual Int_t	SetBranchAddress (const char bname, void add, TBranch **ptr=0)
	Set branch address. More...

virtual Int_t	SetBranchAddress (const char bname, void add, TClass *realClass, EDataType datatype, Bool_t isptr)
	Check if bname is already in the status list, and if not, create a TChainElement object and set its address. More...

virtual void	SetBranchStatus (const char bname, Bool_t status=1, UInt_t found=0)
	Set branch status to Process or DoNotProcess. More...

virtual Int_t	SetCacheSize (Long64_t cacheSize=-1)
	Set maximum size of the file cache . More...

virtual void	SetDirectory (TDirectory *dir)
	Remove reference to this chain from current directory and add reference to new directory dir. More...

virtual void	SetEntryList (TEntryList elist, Option_t opt="")
	Set the input entry list (processing the entries of the chain will then be limited to the entries in the list). More...

virtual void	SetEntryListFile (const char filename="", Option_t opt="")
	Set the input entry list (processing the entries of the chain will then be limited to the entries in the list). More...

virtual void	SetEventList (TEventList *evlist)
	This function transfroms the given TEventList into a TEntryList. More...

virtual void	SetMakeClass (Int_t make)
	Set all the branches in this TTree to be in decomposed object mode (also known as MakeClass mode). More...

virtual void	SetName (const char *name)
	Change the name of this TChain. More...

virtual void	SetPacketSize (Int_t size=100)
	Set number of entries per packet for parallel root. More...

virtual void	SetProof (Bool_t on=kTRUE, Bool_t refresh=kFALSE, Bool_t gettreeheader=kFALSE)
	Enable/Disable PROOF processing on the current default Proof (gProof). More...

virtual void	SetWeight (Double_t w=1, Option_t *option="")
	Set chain weight. More...

virtual void	UseCache (Int_t maxCacheSize=10, Int_t pageSize=0)
	Dummy function kept for back compatibility. More...

Public Member Functions inherited from TTree
	TTree ()
	Default constructor and I/O constructor. More...

	TTree (const char name, const char title, Int_t splitlevel=99, TDirectory *dir=gDirectory)
	Normal tree constructor. More...

	TTree (const TTree &tt)=delete

virtual	~TTree ()
	Destructor. More...

void	AddAllocationCount (UInt_t count)

virtual Int_t	AddBranchToCache (const char *bname, Bool_t subbranches=kFALSE)
	Add branch with name bname to the Tree cache. More...

virtual Int_t	AddBranchToCache (TBranch *branch, Bool_t subbranches=kFALSE)
	Add branch b to the Tree cache. More...

void	AddClone (TTree *)
	Add a cloned tree to our list of trees to be notified whenever we change our branch addresses or when we are deleted. More...

virtual TFriendElement *	AddFriend (const char treename, const char filename="")
	Add a TFriendElement to the list of friends. More...

virtual TFriendElement *	AddFriend (const char treename, TFile file)
	Add a TFriendElement to the list of friends. More...

virtual TFriendElement *	AddFriend (TTree tree, const char alias="", Bool_t warn=kFALSE)
	Add a TFriendElement to the list of friends. More...

virtual void	AddTotBytes (Int_t tot)

virtual void	AddZipBytes (Int_t zip)

virtual Long64_t	AutoSave (Option_t *option="")
	AutoSave tree header every fAutoSave bytes. More...

virtual Int_t	Branch (const char *folder, Int_t bufsize=32000, Int_t splitlevel=99)
	Create one branch for each element in the folder. More...

TBranch *	Branch (const char name, char address, const char *leaflist, Int_t bufsize=32000)

template<class T >
TBranch *	Branch (const char name, const char classname, T **addobj, Int_t bufsize=32000, Int_t splitlevel=99)

template<class T >
TBranch *	Branch (const char name, const char classname, T *obj, Int_t bufsize=32000, Int_t splitlevel=99)

virtual TBranch *	Branch (const char name, const char classname, void *addobj, Int_t bufsize=32000, Int_t splitlevel=99)
	Create a new branch with the object of class classname at address addobj. More...

TBranch *	Branch (const char name, int address, const char leaflist, Int_t bufsize=32000)

TBranch *	Branch (const char name, Long_t address, const char leaflist, Int_t bufsize=32000)

template<typename T , std::size_t N>
TBranch *	Branch (const char name, std::array< T, N > obj, Int_t bufsize=32000, Int_t splitlevel=99)

template<class T >
TBranch *	Branch (const char name, T *addobj, Int_t bufsize=32000, Int_t splitlevel=99)
	Add a new branch, and infer the data type from the array `addobj` being passed. More...

template<class T >
TBranch *	Branch (const char name, T obj, Int_t bufsize=32000, Int_t splitlevel=99)
	Add a new branch, and infer the data type from the type of `obj` being passed. More...

virtual TBranch *	Branch (const char name, void address, const char *leaflist, Int_t bufsize=32000)
	Create a new TTree Branch. More...

virtual Int_t	Branch (TCollection list, Int_t bufsize=32000, Int_t splitlevel=99, const char name="")
	Create one branch for each element in the collection. More...

virtual Int_t	Branch (TList *list, Int_t bufsize=32000, Int_t splitlevel=99)
	Deprecated function. Use next function instead. More...

virtual TBranch *	BranchOld (const char name, const char classname, void *addobj, Int_t bufsize=32000, Int_t splitlevel=1)
	Create a new TTree BranchObject. More...

virtual TBranch *	BranchRef ()
	Build the optional branch supporting the TRefTable. More...

virtual TBranch *	Bronch (const char name, const char classname, void *addobj, Int_t bufsize=32000, Int_t splitlevel=99)
	Create a new TTree BranchElement. More...

virtual void	Browse (TBrowser *)
	Browse content of the TTree. More...

virtual Int_t	BuildIndex (const char majorname, const char minorname="0")
	Build a Tree Index (default is TTreeIndex). More...

TStreamerInfo *	BuildStreamerInfo (TClass cl, void pointer=0, Bool_t canOptimize=kTRUE)
	Build StreamerInfo for class cl. More...

virtual TFile *	ChangeFile (TFile *file)
	Called by TTree::Fill() when file has reached its maximum fgMaxTreeSize. More...

virtual TTree *	CloneTree (Long64_t nentries=-1, Option_t *option="")
	Create a clone of this tree and copy nentries. More...

virtual void	CopyAddresses (TTree *, Bool_t undo=kFALSE)
	Set branch addresses of passed tree equal to ours. More...

virtual Long64_t	CopyEntries (TTree tree, Long64_t nentries=-1, Option_t option="")
	Copy nentries from given tree to this tree. More...

virtual TTree *	CopyTree (const char selection, Option_t option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Copy a tree with selection. More...

virtual TBasket *	CreateBasket (TBranch *)
	Create a basket for this tree and given branch. More...

Int_t	Debug () const

virtual void	Delete (Option_t *option="")
	Delete this tree from memory or/and disk. More...

virtual void	DirectoryAutoAdd (TDirectory *)
	Called by TKey and TObject::Clone to automatically add us to a directory when we are read from a file. More...

virtual Long64_t	Draw (const char varexp, const char selection, Option_t *option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Draw expression varexp for specified entries. More...

virtual Long64_t	Draw (const char varexp, const TCut &selection, Option_t option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Draw expression varexp for specified entries. More...

virtual void	Draw (Option_t *opt)
	Default Draw method for all objects. More...

virtual void	DropBaskets ()
	Remove some baskets from memory. More...

virtual Int_t	DropBranchFromCache (const char *bname, Bool_t subbranches=kFALSE)
	Remove the branch with name 'bname' from the Tree cache. More...

virtual Int_t	DropBranchFromCache (TBranch *branch, Bool_t subbranches=kFALSE)
	Remove the branch b from the Tree cache. More...

virtual void	DropBuffers (Int_t nbytes)
	Drop branch buffers to accommodate nbytes below MaxVirtualsize. More...

virtual Int_t	Fill ()
	Fill all branches. More...

virtual TBranch *	FindBranch (const char *name)
	Return the branch that correspond to the path 'branchname', which can include the name of the tree or the omitted name of the parent branches. More...

virtual TLeaf *	FindLeaf (const char *name)
	Find leaf.. More...

virtual Int_t	Fit (const char funcname, const char varexp, const char selection="", Option_t option="", Option_t *goption="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Fit a projected item(s) from a tree. More...

virtual Int_t	FlushBaskets (Bool_t create_cluster=true) const
	Write to disk all the basket that have not yet been individually written and create an event cluster boundary (by default). More...

virtual const char *	GetAlias (const char *aliasName) const
	Returns the expanded value of the alias. Search in the friends if any. More...

UInt_t	GetAllocationCount () const

virtual Long64_t	GetAutoFlush () const

virtual Long64_t	GetAutoSave () const

virtual TBranch *	GetBranch (const char *name)
	Return pointer to the branch with the given name in this tree or its friends. More...

virtual TBranchRef *	GetBranchRef () const

virtual Bool_t	GetBranchStatus (const char *branchname) const
	Return status of branch with name branchname. More...

virtual Long64_t	GetCacheSize () const

virtual Long64_t	GetChainEntryNumber (Long64_t entry) const

virtual Long64_t	GetChainOffset () const

virtual TClusterIterator	GetClusterIterator (Long64_t firstentry)
	Return an iterator over the cluster of baskets starting at firstentry. More...

virtual Bool_t	GetClusterPrefetch () const

TFile *	GetCurrentFile () const
	Return pointer to the current file. More...

Long64_t	GetDebugMax () const

Long64_t	GetDebugMin () const

Int_t	GetDefaultEntryOffsetLen () const

TDirectory *	GetDirectory () const

virtual Long64_t	GetEntries () const

virtual Long64_t	GetEntries (const char *selection)
	Return the number of entries matching the selection. More...

virtual Long64_t	GetEntriesFast () const

virtual Long64_t	GetEntriesFriend () const
	Return pointer to the 1st Leaf named name in any Branch of this Tree or any branch in the list of friend trees. More...

virtual Int_t	GetEntry (Long64_t entry=0, Int_t getall=0)
	Read all branches of entry and return total number of bytes read. More...

virtual TEntryList *	GetEntryList ()
	Returns the entry list assigned to this tree. More...

virtual Long64_t	GetEntryNumber (Long64_t entry) const
	Return entry number corresponding to entry. More...

virtual Long64_t	GetEntryNumberWithBestIndex (Long64_t major, Long64_t minor=0) const
	Return entry number corresponding to major and minor number. More...

virtual Long64_t	GetEntryNumberWithIndex (Long64_t major, Long64_t minor=0) const
	Return entry number corresponding to major and minor number. More...

virtual Int_t	GetEntryWithIndex (Int_t major, Int_t minor=0)
	Read entry corresponding to major and minor number. More...

virtual Long64_t	GetEstimate () const

Int_t	GetEvent (Long64_t entry=0, Int_t getall=0)

TEventList *	GetEventList () const

virtual Int_t	GetFileNumber () const

virtual TTree *	GetFriend (const char *) const
	Return a pointer to the TTree friend whose name or alias is 'friendname. More...

virtual const char *	GetFriendAlias (TTree *) const
	If the 'tree' is a friend, this method returns its alias name. More...

TH1 *	GetHistogram ()

virtual Bool_t	GetImplicitMT ()

virtual Int_t *	GetIndex ()

virtual Double_t *	GetIndexValues ()

ROOT::TIOFeatures	GetIOFeatures () const
	Returns the current set of IO settings. More...

virtual TIterator *	GetIteratorOnAllLeaves (Bool_t dir=kIterForward)
	Creates a new iterator that will go through all the leaves on the tree itself and its friend. More...

virtual TLeaf *	GetLeaf (const char branchname, const char leafname)
	Return pointer to the 1st Leaf named name in any Branch of this Tree or any branch in the list of friend trees. More...

virtual TLeaf *	GetLeaf (const char *name)
	Return pointer to first leaf named. More...

virtual TList *	GetListOfAliases () const

virtual TObjArray *	GetListOfBranches ()

virtual TList *	GetListOfClones ()

virtual TList *	GetListOfFriends () const

virtual TObjArray *	GetListOfLeaves ()

Int_t	GetMakeClass () const

virtual Long64_t	GetMaxEntryLoop () const

virtual Double_t	GetMaximum (const char *columname)
	Return maximum of column with name columname. More...

virtual Long64_t	GetMaxVirtualSize () const

virtual Double_t	GetMinimum (const char *columname)
	Return minimum of column with name columname. More...

virtual Int_t	GetNbranches ()

TObject *	GetNotify () const

virtual Int_t	GetPacketSize () const

virtual TVirtualPerfStats *	GetPerfStats () const

TVirtualTreePlayer *	GetPlayer ()
	Load the TTreePlayer (if not already done). More...

TTreeCache *	GetReadCache (TFile *file) const
	Find and return the TTreeCache registered with the file and which may contain branches for us. More...

TTreeCache *	GetReadCache (TFile *file, Bool_t create)
	Find and return the TTreeCache registered with the file and which may contain branches for us. More...

virtual Long64_t	GetReadEntry () const

virtual Long64_t	GetReadEvent () const

virtual Int_t	GetScanField () const

TTreeFormula *	GetSelect ()

virtual Long64_t	GetSelectedRows ()

Float_t	GetTargetMemoryRatio () const

virtual Int_t	GetTimerInterval () const

virtual Long64_t	GetTotBytes () const

TBuffer *	GetTransientBuffer (Int_t size)
	Returns the transient buffer currently used by this TTree for reading/writing baskets. More...

virtual TTree *	GetTree () const

virtual TVirtualIndex *	GetTreeIndex () const

virtual Int_t	GetTreeNumber () const

virtual Int_t	GetUpdate () const

virtual TList *	GetUserInfo ()
	Return a pointer to the list containing user objects associated to this tree. More...

virtual Double_t *	GetV1 ()

virtual Double_t *	GetV2 ()

virtual Double_t *	GetV3 ()

virtual Double_t *	GetV4 ()

virtual Double_t *	GetVal (Int_t i)

TTreeFormula *	GetVar (Int_t i)

TTreeFormula *	GetVar1 ()

TTreeFormula *	GetVar2 ()

TTreeFormula *	GetVar3 ()

TTreeFormula *	GetVar4 ()

virtual Double_t *	GetW ()

virtual Double_t	GetWeight () const

virtual Long64_t	GetZipBytes () const

virtual void	IncrementTotalBuffers (Int_t nbytes)

Bool_t	IsFolder () const
	Returns kTRUE in case object contains browsable objects (like containers or lists of other objects). More...

virtual Int_t	LoadBaskets (Long64_t maxmemory=2000000000)
	Read in memory all baskets from all branches up to the limit of maxmemory bytes. More...

virtual Long64_t	LoadTree (Long64_t entry)
	Set current entry. More...

virtual Long64_t	LoadTreeFriend (Long64_t entry, TTree *T)
	Load entry on behalf of our master tree, we may use an index. More...

virtual Int_t	MakeClass (const char classname=0, Option_t option="")
	Generate a skeleton analysis class for this tree. More...

virtual Int_t	MakeCode (const char *filename=0)
	Generate a skeleton function for this tree. More...

virtual Int_t	MakeProxy (const char classname, const char macrofilename=0, const char cutfilename=0, const char option=0, Int_t maxUnrolling=3)
	Generate a skeleton analysis class for this Tree using TBranchProxy. More...

virtual Int_t	MakeSelector (const char selector=0, Option_t option="")
	Generate skeleton selector class for this tree. More...

Bool_t	MemoryFull (Int_t nbytes)
	Check if adding nbytes to memory we are still below MaxVirtualsize. More...

virtual Long64_t	Merge (TCollection list, Option_t option="")
	Merge the trees in the TList into this tree. More...

virtual Long64_t	Merge (TCollection list, TFileMergeInfo info)
	Merge the trees in the TList into this tree. More...

virtual Bool_t	Notify ()
	Function called when loading a new class library. More...

TTree &	operator= (const TTree &tt)=delete

virtual void	OptimizeBaskets (ULong64_t maxMemory=10000000, Float_t minComp=1.1, Option_t *option="")
	This function may be called after having filled some entries in a Tree. More...

TPrincipal *	Principal (const char varexp="", const char selection="", Option_t *option="np", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Interface to the Principal Components Analysis class. More...

virtual void	Print (Option_t *option="") const
	Print a summary of the tree contents. More...

virtual void	PrintCacheStats (Option_t *option="") const
	Print statistics about the TreeCache for this tree. More...

virtual Long64_t	Process (const char filename, Option_t option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Process this tree executing the TSelector code in the specified filename. More...

virtual Long64_t	Process (TSelector selector, Option_t option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Process this tree executing the code in the specified selector. More...

virtual Long64_t	Project (const char hname, const char varexp, const char selection="", Option_t option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Make a projection of a tree using selections. More...

virtual TSQLResult *	Query (const char varexp="", const char selection="", Option_t *option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Loop over entries and return a TSQLResult object containing entries following selection. More...

virtual Long64_t	ReadFile (const char filename, const char branchDescriptor="", char delimiter=' ')
	Create or simply read branches from filename. More...

virtual Long64_t	ReadStream (std::istream &inputStream, const char *branchDescriptor="", char delimiter=' ')
	Create or simply read branches from an input stream. More...

virtual void	RecursiveRemove (TObject *obj)
	Make sure that obj (which is being deleted or will soon be) is no longer referenced by this TTree. More...

virtual void	Refresh ()
	Refresh contents of this tree and its branches from the current status on disk. More...

virtual void	RemoveFriend (TTree *)
	Remove a friend from the list of friends. More...

virtual void	Reset (Option_t *option="")
	Reset baskets, buffers and entries count in all branches and leaves. More...

virtual void	ResetAfterMerge (TFileMergeInfo *)
	Resets the state of this TTree after a merge (keep the customization but forget the data). More...

virtual void	ResetBranchAddress (TBranch *)
	Tell all of our branches to set their addresses to zero. More...

virtual void	ResetBranchAddresses ()
	Tell all of our branches to drop their current objects and allocate new ones. More...

virtual Long64_t	Scan (const char varexp="", const char selection="", Option_t *option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Loop over tree entries and print entries passing selection. More...

virtual Bool_t	SetAlias (const char aliasName, const char aliasFormula)
	Set a tree variable alias. More...

virtual void	SetAutoFlush (Long64_t autof=-30000000)
	This function may be called at the start of a program to change the default value for fAutoFlush. More...

virtual void	SetAutoSave (Long64_t autos=-300000000)
	This function may be called at the start of a program to change the default value for fAutoSave (and for SetAutoSave) is -300000000, ie 300 MBytes. More...

virtual void	SetBasketSize (const char *bname, Int_t buffsize=16000)
	Set a branch's basket size. More...

template<class T >
Int_t	SetBranchAddress (const char bname, T add, TBranch *ptr=0)

template<class T >
Int_t	SetBranchAddress (const char bname, T add, TBranch **ptr=0)

virtual Int_t	SetBranchAddress (const char bname, void add, TBranch *ptr, TClass realClass, EDataType datatype, Bool_t isptr)
	Verify the validity of the type of addr before calling SetBranchAddress. More...

virtual Int_t	SetBranchAddress (const char bname, void add, TBranch **ptr=0)
	Change branch address, dealing with clone trees properly. More...

virtual Int_t	SetBranchAddress (const char bname, void add, TClass *realClass, EDataType datatype, Bool_t isptr)
	Verify the validity of the type of addr before calling SetBranchAddress. More...

virtual void	SetBranchStatus (const char bname, Bool_t status=1, UInt_t found=0)
	Set branch status to Process or DoNotProcess. More...

virtual Int_t	SetCacheEntryRange (Long64_t first, Long64_t last)
	interface to TTreeCache to set the cache entry range More...

virtual void	SetCacheLearnEntries (Int_t n=10)
	Interface to TTreeCache to set the number of entries for the learning phase. More...

virtual Int_t	SetCacheSize (Long64_t cachesize=-1)
	Set maximum size of the file cache . More...

virtual void	SetChainOffset (Long64_t offset=0)

virtual void	SetCircular (Long64_t maxEntries)
	Enable/Disable circularity for this tree. More...

virtual void	SetClusterPrefetch (Bool_t enabled)

virtual void	SetDebug (Int_t level=1, Long64_t min=0, Long64_t max=9999999)
	Set the debug level and the debug range. More...

virtual void	SetDefaultEntryOffsetLen (Int_t newdefault, Bool_t updateExisting=kFALSE)
	Update the default value for the branch's fEntryOffsetLen. More...

virtual void	SetDirectory (TDirectory *dir)
	Change the tree's directory. More...

virtual Long64_t	SetEntries (Long64_t n=-1)
	Change number of entries in the tree. More...

virtual void	SetEntryList (TEntryList list, Option_t opt="")
	Set an EntryList. More...

virtual void	SetEstimate (Long64_t nentries=1000000)
	Set number of entries to estimate variable limits. More...

virtual void	SetEventList (TEventList *list)
	This function transfroms the given TEventList into a TEntryList The new TEntryList is owned by the TTree and gets deleted when the tree is deleted. More...

virtual void	SetFileNumber (Int_t number=0)
	Set fFileNumber to number. More...

virtual void	SetImplicitMT (Bool_t enabled)

ROOT::TIOFeatures	SetIOFeatures (const ROOT::TIOFeatures &)
	Provide the end-user with the ability to enable/disable various experimental IO features for this TTree. More...

virtual void	SetMakeClass (Int_t make)
	Set all the branches in this TTree to be in decomposed object mode (also known as MakeClass mode). More...

virtual void	SetMaxEntryLoop (Long64_t maxev=kMaxEntries)

virtual void	SetMaxVirtualSize (Long64_t size=0)

virtual void	SetName (const char *name)
	Change the name of this tree. More...

virtual void	SetNotify (TObject *obj)
	Sets the address of the object to be notified when the tree is loaded. More...

virtual void	SetObject (const char name, const char title)
	Change the name and title of this tree. More...

virtual void	SetParallelUnzip (Bool_t opt=kTRUE, Float_t RelSize=-1)
	Enable or disable parallel unzipping of Tree buffers. More...

virtual void	SetPerfStats (TVirtualPerfStats *perf)
	Set perf stats. More...

virtual void	SetScanField (Int_t n=50)

void	SetTargetMemoryRatio (Float_t ratio)

virtual void	SetTimerInterval (Int_t msec=333)

virtual void	SetTreeIndex (TVirtualIndex *index)
	The current TreeIndex is replaced by the new index. More...

virtual void	SetUpdate (Int_t freq=0)

virtual void	SetWeight (Double_t w=1, Option_t *option="")
	Set tree weight. More...

virtual void	Show (Long64_t entry=-1, Int_t lenmax=20)
	Print values of all active leaves for entry. More...

virtual void	StartViewer ()
	Start the TTreeViewer on this tree. More...

virtual Int_t	StopCacheLearningPhase ()
	Stop the cache learning phase. More...

virtual Int_t	UnbinnedFit (const char funcname, const char varexp, const char selection="", Option_t option="", Long64_t nentries=kMaxEntries, Long64_t firstentry=0)
	Unbinned fit of one or more variable(s) from a tree. More...

void	UseCurrentStyle ()
	Replace current attributes by current style. More...

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0)
	Write this object to the current directory. More...

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const
	Write this object to the current directory. More...

Public Member Functions inherited from TNamed
	TNamed ()

	TNamed (const char name, const char title)

	TNamed (const TNamed &named)
	TNamed copy ctor. More...

	TNamed (const TString &name, const TString &title)

virtual	~TNamed ()
	TNamed destructor. More...

virtual void	Clear (Option_t *option="")
	Set name and title to empty strings (""). More...

virtual TObject *	Clone (const char *newname="") const
	Make a clone of an object using the Streamer facility. More...

virtual Int_t	Compare (const TObject *obj) const
	Compare two TNamed objects. More...

virtual void	Copy (TObject &named) const
	Copy this to obj. More...

virtual void	FillBuffer (char *&buffer)
	Encode TNamed into output buffer. More...

virtual const char *	GetName () const
	Returns name of object. More...

virtual const char *	GetTitle () const
	Returns title of object. More...

virtual ULong_t	Hash () const
	Return hash value for this object. More...

virtual Bool_t	IsSortable () const

virtual void	ls (Option_t *option="") const
	List TNamed name and title. More...

TNamed &	operator= (const TNamed &rhs)
	TNamed assignment operator. More...

virtual void	Print (Option_t *option="") const
	Print TNamed name and title. More...

virtual void	SetName (const char *name)
	Set the name of the TNamed. More...

virtual void	SetNameTitle (const char name, const char title)
	Set all the TNamed parameters (name and title). More...

virtual void	SetTitle (const char *title="")
	Set the title of the TNamed. More...

virtual Int_t	Sizeof () const
	Return size of the TNamed part of the TObject. More...

Public Member Functions inherited from TObject
	TObject ()
	TObject constructor. More...

	TObject (const TObject &object)
	TObject copy ctor. More...

virtual	~TObject ()
	TObject destructor. More...

void	AbstractMethod (const char *method) const
	Use this method to implement an "abstract" method that you don't want to leave purely abstract. More...

virtual void	AppendPad (Option_t *option="")
	Append graphics object to current pad. More...

virtual void	Browse (TBrowser *b)
	Browse object. May be overridden for another default action. More...

ULong_t	CheckedHash ()
	Check and record whether this class has a consistent Hash/RecursiveRemove setup (*) and then return the regular Hash value for this object. More...

virtual const char *	ClassName () const
	Returns name of class to which the object belongs. More...

virtual void	Clear (Option_t *="")

virtual TObject *	Clone (const char *newname="") const
	Make a clone of an object using the Streamer facility. More...

virtual Int_t	Compare (const TObject *obj) const
	Compare abstract method. More...

virtual void	Copy (TObject &object) const
	Copy this to obj. More...

virtual void	Delete (Option_t *option="")
	Delete this object. More...

virtual Int_t	DistancetoPrimitive (Int_t px, Int_t py)
	Computes distance from point (px,py) to the object. More...

virtual void	Draw (Option_t *option="")
	Default Draw method for all objects. More...

virtual void	DrawClass () const
	Draw class inheritance tree of the class to which this object belongs. More...

virtual TObject *	DrawClone (Option_t *option="") const
	Draw a clone of this object in the current selected pad for instance with: `gROOT->SetSelectedPad(gPad)`. More...

virtual void	Dump () const
	Dump contents of object on stdout. More...

virtual void	Error (const char method, const char msgfmt,...) const
	Issue error message. More...

virtual void	Execute (const char method, const char params, Int_t *error=0)
	Execute method on this object with the given parameter string, e.g. More...

virtual void	Execute (TMethod method, TObjArray params, Int_t *error=0)
	Execute method on this object with parameters stored in the TObjArray. More...

virtual void	ExecuteEvent (Int_t event, Int_t px, Int_t py)
	Execute action corresponding to an event at (px,py). More...

virtual void	Fatal (const char method, const char msgfmt,...) const
	Issue fatal error message. More...

virtual TObject *	FindObject (const char *name) const
	Must be redefined in derived classes. More...

virtual TObject *	FindObject (const TObject *obj) const
	Must be redefined in derived classes. More...

virtual Option_t *	GetDrawOption () const
	Get option used by the graphics system to draw this object. More...

virtual const char *	GetIconName () const
	Returns mime type name of object. More...

virtual const char *	GetName () const
	Returns name of object. More...

virtual char *	GetObjectInfo (Int_t px, Int_t py) const
	Returns string containing info about the object at position (px,py). More...

virtual Option_t *	GetOption () const

virtual const char *	GetTitle () const
	Returns title of object. More...

virtual UInt_t	GetUniqueID () const
	Return the unique object id. More...

virtual Bool_t	HandleTimer (TTimer *timer)
	Execute action in response of a timer timing out. More...

virtual ULong_t	Hash () const
	Return hash value for this object. More...

Bool_t	HasInconsistentHash () const
	Return true is the type of this object is known to have an inconsistent setup for Hash and RecursiveRemove (i.e. More...

virtual void	Info (const char method, const char msgfmt,...) const
	Issue info message. More...

virtual Bool_t	InheritsFrom (const char *classname) const
	Returns kTRUE if object inherits from class "classname". More...

virtual Bool_t	InheritsFrom (const TClass *cl) const
	Returns kTRUE if object inherits from TClass cl. More...

virtual void	Inspect () const
	Dump contents of this object in a graphics canvas. More...

void	InvertBit (UInt_t f)

virtual Bool_t	IsEqual (const TObject *obj) const
	Default equal comparison (objects are equal if they have the same address in memory). More...

virtual Bool_t	IsFolder () const
	Returns kTRUE in case object contains browsable objects (like containers or lists of other objects). More...

R__ALWAYS_INLINE Bool_t	IsOnHeap () const

virtual Bool_t	IsSortable () const

R__ALWAYS_INLINE Bool_t	IsZombie () const

virtual void	ls (Option_t *option="") const
	The ls function lists the contents of a class on stdout. More...

void	MayNotUse (const char *method) const
	Use this method to signal that a method (defined in a base class) may not be called in a derived class (in principle against good design since a child class should not provide less functionality than its parent, however, sometimes it is necessary). More...

virtual Bool_t	Notify ()
	This method must be overridden to handle object notification. More...

void	Obsolete (const char method, const char asOfVers, const char *removedFromVers) const
	Use this method to declare a method obsolete. More...

void	operator delete (void *ptr)
	Operator delete. More...

void	operator delete[] (void *ptr)
	Operator delete []. More...

void *	operator new (size_t sz)

void *	operator new (size_t sz, void *vp)

void *	operator new[] (size_t sz)

void *	operator new[] (size_t sz, void *vp)

TObject &	operator= (const TObject &rhs)
	TObject assignment operator. More...

virtual void	Paint (Option_t *option="")
	This method must be overridden if a class wants to paint itself. More...

virtual void	Pop ()
	Pop on object drawn in a pad to the top of the display list. More...

virtual void	Print (Option_t *option="") const
	This method must be overridden when a class wants to print itself. More...

virtual Int_t	Read (const char *name)
	Read contents of object with specified name from the current directory. More...

virtual void	RecursiveRemove (TObject *obj)
	Recursively remove this object from a list. More...

void	ResetBit (UInt_t f)

virtual void	SaveAs (const char filename="", Option_t option="") const
	Save this object in the file specified by filename. More...

virtual void	SavePrimitive (std::ostream &out, Option_t *option="")
	Save a primitive as a C++ statement(s) on output stream "out". More...

void	SetBit (UInt_t f)

void	SetBit (UInt_t f, Bool_t set)
	Set or unset the user status bits as specified in f. More...

virtual void	SetDrawOption (Option_t *option="")
	Set drawing option for object. More...

virtual void	SetUniqueID (UInt_t uid)
	Set the unique object id. More...

virtual void	SysError (const char method, const char msgfmt,...) const
	Issue system error message. More...

R__ALWAYS_INLINE Bool_t	TestBit (UInt_t f) const

Int_t	TestBits (UInt_t f) const

virtual void	UseCurrentStyle ()
	Set current style settings in this object This function is called when either TCanvas::UseCurrentStyle or TROOT::ForceStyle have been invoked. More...

virtual void	Warning (const char method, const char msgfmt,...) const
	Issue warning message. More...

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0)
	Write this object to the current directory. More...

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const
	Write this object to the current directory. More...

Public Member Functions inherited from TAttLine
	TAttLine ()
	AttLine default constructor. More...

	TAttLine (Color_t lcolor, Style_t lstyle, Width_t lwidth)
	AttLine normal constructor. More...

virtual	~TAttLine ()
	AttLine destructor. More...

void	Copy (TAttLine &attline) const
	Copy this line attributes to a new TAttLine. More...

Int_t	DistancetoLine (Int_t px, Int_t py, Double_t xp1, Double_t yp1, Double_t xp2, Double_t yp2)
	Compute distance from point px,py to a line. More...

virtual Color_t	GetLineColor () const
	Return the line color. More...

virtual Style_t	GetLineStyle () const
	Return the line style. More...

virtual Width_t	GetLineWidth () const
	Return the line width. More...

virtual void	Modify ()
	Change current line attributes if necessary. More...

virtual void	ResetAttLine (Option_t *option="")
	Reset this line attributes to default values. More...

virtual void	SaveLineAttributes (std::ostream &out, const char *name, Int_t coldef=1, Int_t stydef=1, Int_t widdef=1)
	Save line attributes as C++ statement(s) on output stream out. More...

virtual void	SetLineAttributes ()
	Invoke the DialogCanvas Line attributes. More...

virtual void	SetLineColor (Color_t lcolor)
	Set the line color. More...

virtual void	SetLineColorAlpha (Color_t lcolor, Float_t lalpha)
	Set a transparent line color. More...

virtual void	SetLineStyle (Style_t lstyle)
	Set the line style. More...

virtual void	SetLineWidth (Width_t lwidth)
	Set the line width. More...

Public Member Functions inherited from TAttFill
	TAttFill ()
	AttFill default constructor. More...

	TAttFill (Color_t fcolor, Style_t fstyle)
	AttFill normal constructor. More...

virtual	~TAttFill ()
	AttFill destructor. More...

void	Copy (TAttFill &attfill) const
	Copy this fill attributes to a new TAttFill. More...

virtual Color_t	GetFillColor () const
	Return the fill area color. More...

virtual Style_t	GetFillStyle () const
	Return the fill area style. More...

virtual Bool_t	IsTransparent () const

virtual void	Modify ()
	Change current fill area attributes if necessary. More...

virtual void	ResetAttFill (Option_t *option="")
	Reset this fill attributes to default values. More...

virtual void	SaveFillAttributes (std::ostream &out, const char *name, Int_t coldef=1, Int_t stydef=1001)
	Save fill attributes as C++ statement(s) on output stream out. More...

virtual void	SetFillAttributes ()
	Invoke the DialogCanvas Fill attributes. More...

virtual void	SetFillColor (Color_t fcolor)
	Set the fill area color. More...

virtual void	SetFillColorAlpha (Color_t fcolor, Float_t falpha)
	Set a transparent fill color. More...

virtual void	SetFillStyle (Style_t fstyle)
	Set the fill area style. More...

Public Member Functions inherited from TAttMarker
	TAttMarker ()
	TAttMarker default constructor. More...

	TAttMarker (Color_t color, Style_t style, Size_t msize)
	TAttMarker normal constructor. More...

virtual	~TAttMarker ()
	TAttMarker destructor. More...

void	Copy (TAttMarker &attmarker) const
	Copy this marker attributes to a new TAttMarker. More...

virtual Color_t	GetMarkerColor () const
	Return the marker color. More...

virtual Size_t	GetMarkerSize () const
	Return the marker size. More...

virtual Style_t	GetMarkerStyle () const
	Return the marker style. More...

virtual void	Modify ()
	Change current marker attributes if necessary. More...

virtual void	ResetAttMarker (Option_t *toption="")
	Reset this marker attributes to the default values. More...

virtual void	SaveMarkerAttributes (std::ostream &out, const char *name, Int_t coldef=1, Int_t stydef=1, Int_t sizdef=1)
	Save line attributes as C++ statement(s) on output stream out. More...

virtual void	SetMarkerAttributes ()
	Invoke the DialogCanvas Marker attributes. More...

virtual void	SetMarkerColor (Color_t mcolor=1)
	Set the marker color. More...

virtual void	SetMarkerColorAlpha (Color_t mcolor, Float_t malpha)
	Set a transparent marker color. More...

virtual void	SetMarkerSize (Size_t msize=1)
	Set the marker size. More...

virtual void	SetMarkerStyle (Style_t mstyle=1)
	Set the marker style. More...

Static Public Attributes
static constexpr auto	kBigNumber = TTree::kMaxEntries

Static Public Attributes inherited from TTree
static constexpr Long64_t	kMaxEntries = TVirtualTreePlayer::kMaxEntries

Protected Member Functions
void	InvalidateCurrentTree ()
	Set the TTree to be reloaded as soon as possible. More...

void	ReleaseChainProof ()

Protected Member Functions inherited from TTree
virtual TBranch *	BranchImp (const char branchname, const char classname, TClass ptrClass, void addobj, Int_t bufsize, Int_t splitlevel)
	Same as TTree::Branch() with added check that addobj matches className. More...

virtual TBranch *	BranchImp (const char branchname, TClass ptrClass, void *addobj, Int_t bufsize, Int_t splitlevel)
	Same as TTree::Branch but automatic detection of the class name. More...

virtual TBranch *	BranchImpArr (const char branchname, EDataType datatype, std::size_t N, void addobj, Int_t bufsize, Int_t splitlevel)

virtual TBranch *	BranchImpRef (const char branchname, const char classname, TClass ptrClass, void addobj, Int_t bufsize, Int_t splitlevel)
	Same as TTree::Branch but automatic detection of the class name. More...

virtual TBranch *	BranchImpRef (const char branchname, TClass ptrClass, EDataType datatype, void *addobj, Int_t bufsize, Int_t splitlevel)
	Same as TTree::Branch but automatic detection of the class name. More...

virtual TBranch *	BronchExec (const char name, const char classname, void *addobj, Bool_t isptrptr, Int_t bufsize, Int_t splitlevel)
	Helper function implementing TTree::Bronch and TTree::Branch(const char *name, T &obj);. More...

virtual Int_t	CheckBranchAddressType (TBranch branch, TClass ptrClass, EDataType datatype, Bool_t ptr)
	Check whether or not the address described by the last 3 parameters matches the content of the branch. More...

Long64_t	GetCacheAutoSize (Bool_t withDefault=kFALSE) const
	Used for automatic sizing of the cache. More...

virtual TLeaf *	GetLeafImpl (const char branchname, const char leafname)
	Return pointer to the 1st Leaf named name in any Branch of this Tree or any branch in the list of friend trees. More...

char	GetNewlineValue (std::istream &inputStream)
	Determine which newline this file is using. More...

void	ImportClusterRanges (TTree *fromtree)
	Appends the cluster range information stored in 'fromtree' to this tree, including the value of fAutoFlush. More...

virtual void	KeepCircular ()
	Keep a maximum of fMaxEntries in memory. More...

void	MoveReadCache (TFile src, TDirectory dir)
	Move a cache from a file to the current file in dir. More...

Int_t	SetBranchAddressImp (TBranch branch, void addr, TBranch **ptr)
	Change branch address, dealing with clone trees properly. More...

Int_t	SetCacheSizeAux (Bool_t autocache=kTRUE, Long64_t cacheSize=0)
	Set the size of the file cache and create it if possible. More...

Protected Member Functions inherited from TObject
virtual void	DoError (int level, const char location, const char fmt, va_list va) const
	Interface to ErrorHandler (protected). More...

void	MakeZombie ()

Protected Attributes
Bool_t	fCanDeleteRefs
	! If true, TProcessIDs are deleted when closing a file More...

TFile *	fFile
	! Pointer to current file (We own the file). More...

TObjArray *	fFiles
	-> List of file names containing the trees (TChainElement, owned) More...

Int_t	fNtrees
	Number of trees. More...

TChain *	fProofChain
	! chain proxy when going to be processed by PROOF More...

TList *	fStatus
	-> List of active/inactive branches (TChainElement, owned) More...

TTree *	fTree
	! Pointer to current tree (Note: We do not own this tree.) More...

Int_t	fTreeNumber
	! Current Tree number in fTreeOffset table More...

Long64_t *	fTreeOffset
	[fTreeOffsetLen] Array of variables More...

Int_t	fTreeOffsetLen
	Current size of fTreeOffset array. More...

Protected Attributes inherited from TTree
TList *	fAliases
	List of aliases for expressions based on the tree branches. More...

std::atomic< UInt_t >	fAllocationCount {0}
	indicates basket should be resized to exact memory usage, but causes significant More...

Long64_t	fAutoFlush
	Auto-flush tree when fAutoFlush entries written or -fAutoFlush (compressed) bytes produced. More...

Long64_t	fAutoSave
	Autosave tree when fAutoSave entries written or -fAutoSave (compressed) bytes produced. More...

TObjArray	fBranches
	List of Branches. More...

TBranchRef *	fBranchRef
	Branch supporting the TRefTable (if any) More...

Bool_t	fCacheDoAutoInit
	! true if cache auto creation or resize check is needed More...

Bool_t	fCacheDoClusterPrefetch
	! true if cache is prefetching whole clusters More...

Long64_t	fCacheSize
	! Maximum size of file buffers More...

Bool_t	fCacheUserSet
	! true if the cache setting was explicitly given by user More...

Long64_t	fChainOffset
	! Offset of 1st entry of this Tree in a TChain More...

TList *	fClones
	! List of cloned trees which share our addresses More...

Long64_t *	fClusterRangeEnd
	[fNClusterRange] Last entry of a cluster range. More...

Long64_t *	fClusterSize
	[fNClusterRange] Number of entries in each cluster for a given range. More...

Int_t	fDebug
	! Debug level More...

Long64_t	fDebugMax
	! Last entry number to debug More...

Long64_t	fDebugMin
	! First entry number to debug More...

Int_t	fDefaultEntryOffsetLen
	Initial Length of fEntryOffset table in the basket buffers. More...

TDirectory *	fDirectory
	! Pointer to directory holding this tree More...

Long64_t	fEntries
	Number of entries. More...

TEntryList *	fEntryList
	! Pointer to event selection list (if one) More...

Long64_t	fEstimate
	Number of entries to estimate histogram limits. More...

TEventList *	fEventList
	! Pointer to event selection list (if one) More...

Int_t	fFileNumber
	! current file number (if file extensions) More...

Long64_t	fFlushedBytes
	Number of auto-flushed bytes. More...

UInt_t	fFriendLockStatus
	! Record which method is locking the friend recursion More...

TList *	fFriends
	pointer to list of friend elements More...

Bool_t	fIMTEnabled
	! true if implicit multi-threading is enabled for this tree More...

TArrayI	fIndex
	Index of sorted values. More...

TArrayD	fIndexValues
	Sorted index values. More...

TIOFeatures	fIOFeatures {0}
	IO features to define for newly-written baskets and branches. More...

TObjArray	fLeaves
	Direct pointers to individual branch leaves. More...

Int_t	fMakeClass
	! not zero when processing code generated by MakeClass More...

Int_t	fMaxClusterRange
	! Memory allocated for the cluster range. More...

Long64_t	fMaxEntries
	Maximum number of entries in case of circular buffers. More...

Long64_t	fMaxEntryLoop
	Maximum number of entries to process. More...

Long64_t	fMaxVirtualSize
	Maximum total size of buffers kept in memory. More...

Int_t	fNClusterRange
	Number of Cluster range in addition to the one defined by 'AutoFlush'. More...

UInt_t	fNEntriesSinceSorting
	! Number of entries processed since the last re-sorting of branches More...

Int_t	fNfill
	! Local for EntryLoop More...

TObject *	fNotify
	! Object to be notified when loading a Tree More...

Int_t	fPacketSize
	! Number of entries in one packet for parallel root More...

TVirtualPerfStats *	fPerfStats
	! pointer to the current perf stats object More...

TVirtualTreePlayer *	fPlayer
	! Pointer to current Tree player More...

Long64_t	fReadEntry
	! Number of the entry being processed More...

Long64_t	fSavedBytes
	Number of autosaved bytes. More...

Int_t	fScanField
	Number of runs before prompting in Scan. More...

std::vector< TBranch * >	fSeqBranches
	! Branches to be processed sequentially when IMT is on More...

std::vector< std::pair< Long64_t, TBranch * > >	fSortedBranches
	! Branches to be processed in parallel when IMT is on, sorted by average task time More...

Float_t	fTargetMemoryRatio {1.1f}
	! Ratio for memory usage in uncompressed buffers versus actual occupancy. More...

Int_t	fTimerInterval
	Timer interval in milliseconds. More...

std::atomic< Long64_t >	fTotalBuffers
	! Total number of bytes in branch buffers More...

Long64_t	fTotBytes
	Total number of bytes in all branches before compression. More...

TBuffer *	fTransientBuffer
	! Pointer to the current transient buffer. More...

TVirtualIndex *	fTreeIndex
	Pointer to the tree Index (if any) More...

Int_t	fUpdate
	Update frequency for EntryLoop. More...

TList *	fUserInfo
	pointer to a list of user objects associated to this Tree More...

Double_t	fWeight
	Tree weight (see TTree::SetWeight) More...

Long64_t	fZipBytes
	Total number of bytes in all branches after compression. More...

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

Protected Attributes inherited from TAttLine
Color_t	fLineColor
	Line color. More...

Style_t	fLineStyle
	Line style. More...

Width_t	fLineWidth
	Line width. More...

Protected Attributes inherited from TAttFill
Color_t	fFillColor
	Fill area color. More...

Style_t	fFillStyle
	Fill area style. More...

Protected Attributes inherited from TAttMarker
Color_t	fMarkerColor
	Marker color. More...

Size_t	fMarkerSize
	Marker size. More...

Style_t	fMarkerStyle
	Marker style. More...

Private Member Functions
	TChain (const TChain &)

TChain &	operator= (const TChain &)

void	ParseTreeFilename (const char *name, TString &filename, TString &treename, TString &query, TString &suffix, Bool_t wildcards) const
	Get the tree url or filename and other information from the name. More...

Additional Inherited Members
Static Public Member Functions inherited from TTree
static Int_t	GetBranchStyle ()
	Static function returning the current branch style. More...

static Long64_t	GetMaxTreeSize ()
	Static function which returns the tree file size limit in bytes. More...

static TTree *	MergeTrees (TList list, Option_t option="")
	Static function merging the trees in the TList into a new tree. More...

static void	SetBranchStyle (Int_t style=1)
	Set the current branch style. More...

static void	SetMaxTreeSize (Long64_t maxsize=100000000000LL)
	Set the maximum size in bytes of a Tree file (static function). More...

Static Public Member Functions inherited from TObject
static Long_t	GetDtorOnly ()
	Return destructor only flag. More...

static Bool_t	GetObjectStat ()
	Get status of object stat flag. More...

static void	SetDtorOnly (void *obj)
	Set destructor only flag. More...

static void	SetObjectStat (Bool_t stat)
	Turn on/off tracking of objects in the TObjectTable. More...

Protected Types inherited from TTree
enum	ELockStatusBits { kFindBranch = BIT(0) , kFindLeaf = BIT(1) , kGetAlias = BIT(2) , kGetBranch = BIT(3) , kGetEntry = BIT(4) , kGetEntryWithIndex = BIT(5) , kGetFriend = BIT(6) , kGetFriendAlias = BIT(7) , kGetLeaf = BIT(8) , kLoadTree = BIT(9) , kPrint = BIT(10) , kRemoveFriend = BIT(11) , kSetBranchStatus = BIT(12) }

Static Protected Attributes inherited from TTree
static Int_t	fgBranchStyle = 1
	Old/New branch style. More...

static Long64_t	fgMaxTreeSize = 100000000000LL
	Maximum size of a file containing a Tree. More...

#include <TChain.h>

Inheritance diagram for TChain:

[legend]

Member Enumeration Documentation

◆ EStatusBits

enum TChain::EStatusBits

Enumerator
kGlobalWeight
kAutoDelete
kProofUptodate
kProofLite

Definition at line 59 of file TChain.h.

Constructor & Destructor Documentation

◆ TChain() [1/3]

TChain::TChain ( const TChain & )

private

◆ TChain() [2/3]

TChain::TChain ( )

Default constructor.

Definition at line 64 of file TChain.cxx.

◆ TChain() [3/3]

TChain::TChain	(	const char *	name,
		const char *	title = `""`
	)

Create a chain.

A TChain is a collection of TFile objects. the first parameter "name" is the name of the TTree object in the files added with Add. Use TChain::Add to add a new element to this chain.

In case the Tree is in a subdirectory, do, eg:

TChain ch("subdir/treename");

TChain

A chain is a collection of files containing TTree objects.

Definition: TChain.h:34

Example: Suppose we have 3 files f1.root, f2.root and f3.root. Each file contains a TTree object named "T".

TChain ch("T");  creates a chain to process a Tree called "T"
ch.Add("f1.root");
ch.Add("f2.root");
ch.Add("f3.root");
ch.Draw("x");

The Draw function above will process the variable "x" in Tree "T" reading sequentially the 3 files in the chain ch.

The TChain data structure:

Each TChainElement has a name equal to the tree name of this TChain and a title equal to the file name. So, to loop over the TFiles that have been added to this chain:

TObjArray *fileElements=chain->GetListOfFiles();
TIter next(fileElements);
TChainElement *chEl=0;
while (( chEl=(TChainElement*)next() )) {
   TFile f(chEl->GetTitle());
   ... do something with f ...
}

Definition at line 138 of file TChain.cxx.

◆ ~TChain()

TChain::~TChain ( )

virtual

Destructor.

Definition at line 177 of file TChain.cxx.

Member Function Documentation

◆ Add() [1/2]

Int_t TChain::Add	(	const char *	name,
		Long64_t	nentries = `TTree::kMaxEntries`
	)

virtual

Add a new file to this chain.

Argument name may have either of two set of formats. The first:

[//machine]/path/file_name[?query[#tree_name]]

or [//machine]/path/file_name.root[.oext][/tree_name]

If tree_name is missing the chain name will be assumed. Tagging the tree_name with a slash [/tree_name] is only supported for backward compatibility; it requires the file name to contain the string '.root' and its use is deprecated. Wildcard treatment is triggered by the any of the special characters []*? which may be used in the file name, eg. specifying "xxx*.root" adds all files starting with xxx in the current file system directory.

Alternatively name may have the format of a url, eg.

    root://machine/path/file_name[?query[#tree_name]]
or  root://machine/path/file_name
or  root://machine/path/file_name.root[.oext]/tree_name
or  root://machine/path/file_name.root[.oext]/tree_name?query

where "query" is to be interpreted by the remote server. Wildcards may be supported in urls, depending on the protocol plugin and the remote server. http or https urls can contain a query identifier without tree_name, but generally urls can not be written with them because of ambiguity with the wildcard character. (Also see the documentation for TChain::AddFile, which does not support wildcards but allows the url name to contain query). Again, tagging the tree_name with a slash [/tree_name] is only supported for backward compatibility; it requires the file name ot contain the string '.root' and its use is deprecated.

NB. To add all the files of a TChain to a chain, use Add(TChain *chain).

A. if nentries <= 0, the file is connected and the tree header read in memory to get the number of entries.

B. if (nentries > 0, the file is not connected, nentries is assumed to be the number of entries in the file. In this case, no check is made that the file exists and the Tree existing in the file. This second mode is interesting in case the number of entries in the file is already stored in a run data base for example.

C. if (nentries == TTree::kMaxEntries) (default), the file is not connected. the number of entries in each file will be read only when the file will need to be connected to read an entry. This option is the default and very efficient if one process the chain sequentially. Note that in case TChain::GetEntry(entry) is called and entry refers to an entry in the 3rd file, for example, this forces the Tree headers in the first and second file to be read to find the number of entries in these files. Note that if one calls TChain::GetEntriesFast() after having created a chain with this default, GetEntriesFast will return TTree::kMaxEntries! TChain::GetEntries will force of the Tree headers in the chain to be read to read the number of entries in each Tree.

D. The TChain data structure Each TChainElement has a name equal to the tree name of this TChain and a title equal to the file name. So, to loop over the TFiles that have been added to this chain:

TObjArray *fileElements=chain->GetListOfFiles();
TIter next(fileElements);
TChainElement *chEl=0;
while (( chEl=(TChainElement*)next() )) {
   TFile f(chEl->GetTitle());
   ... do something with f ...
}

Return value:

If nentries>0 (including the default of TTree::kMaxEntries) and no wildcarding is used, ALWAYS returns 1 without regard to whether the file exists or contains the correct tree.
If wildcarding is used, regardless of the value of nentries, returns the number of files matching the name without regard to whether they contain the correct tree.
If nentries<=0 and wildcarding is not used, return 1 if the file exists and contains the correct tree and 0 otherwise.

Definition at line 346 of file TChain.cxx.

◆ Add() [2/2]

Int_t TChain::Add ( TChain * chain )

virtual

Add all files referenced by the passed chain to this chain.

The function returns the total number of files connected.

Definition at line 223 of file TChain.cxx.

◆ AddFile()

Int_t TChain::AddFile	(	const char *	name,
		Long64_t	nentries = `TTree::kMaxEntries`,
		const char *	tname = `""`
	)

virtual

Add a new file to this chain.

Filename formats are similar to TChain::Add. Wildcards are not applied. urls may also contain query and fragment identifiers where the tree name can be specified in the url fragment.

eg.

root://machine/path/file_name[?query[#tree_name]]

root://machine/path/file_name.root[.oext]/tree_name[?query]

If tree_name is given as a part of the file name it is used to as the name of the tree to load from the file. Otherwise if tname argument is specified the chain will load the tree named tname from the file, otherwise the original treename specified in the TChain constructor will be used. Tagging the tree_name with a slash [/tree_name] is only supported for backward compatibility; it requires the file name ot contain the string '.root' and its use is deprecated.

A. If nentries <= 0, the file is opened and the tree header read into memory to get the number of entries.

B. If nentries > 0, the file is not opened, and nentries is assumed to be the number of entries in the file. In this case, no check is made that the file exists nor that the tree exists in the file. This second mode is interesting in case the number of entries in the file is already stored in a run database for example.

C. If nentries == TTree::kMaxEntries (default), the file is not opened. The number of entries in each file will be read only when the file is opened to read an entry. This option is the default and very efficient if one processes the chain sequentially. Note that in case GetEntry(entry) is called and entry refers to an entry in the third file, for example, this forces the tree headers in the first and second file to be read to find the number of entries in those files. Note that if one calls GetEntriesFast() after having created a chain with this default, GetEntriesFast() will return TTree::kMaxEntries! Using the GetEntries() function instead will force all of the tree headers in the chain to be read to read the number of entries in each tree.

D. The TChain data structure Each TChainElement has a name equal to the tree name of this TChain and a title equal to the file name. So, to loop over the TFiles that have been added to this chain:

TObjArray *fileElements=chain->GetListOfFiles();
TIter next(fileElements);
TChainElement *chEl=0;
while (( chEl=(TChainElement*)next() )) {
   TFile f(chEl->GetTitle());
   ... do something with f ...
}

The function returns 1 if the file is successfully connected, 0 otherwise.

Definition at line 458 of file TChain.cxx.

◆ AddFileInfoList()

Int_t TChain::AddFileInfoList	(	TCollection *	filelist,
		Long64_t	nfiles = `TTree::kMaxEntries`
	)

virtual

Add all files referenced in the list to the chain.

The object type in the list must be either TFileInfo or TObjString or TUrl . The function return 1 if successful, 0 otherwise.

Definition at line 555 of file TChain.cxx.

◆ AddFriend() [1/3]

TFriendElement * TChain::AddFriend	(	const char *	chain,
		const char *	dummy = `""`
	)

virtual

Add a TFriendElement to the list of friends of this chain.

A TChain has a list of friends similar to a tree (see TTree::AddFriend). You can add a friend to a chain with the TChain::AddFriend method, and you can retrieve the list of friends with TChain::GetListOfFriends. This example has four chains each has 20 ROOT trees from 20 ROOT files.

TChain ch("t"); // a chain with 20 trees from 20 files
TChain ch1("t1");
TChain ch2("t2");
TChain ch3("t3");

Now we can add the friends to the first chain.

ch.AddFriend("t1")
ch.AddFriend("t2")
ch.AddFriend("t3")

The parameter is the name of friend chain (the name of a chain is always the name of the tree from which it was created). The original chain has access to all variable in its friends. We can use the TChain::Draw method as if the values in the friends were in the original chain. To specify the chain to use in the Draw method, use the syntax:

If the variable name is enough to uniquely identify the variable, you can leave out the chain and/or branch name. For example, this generates a 3-d scatter plot of variable "var" in the TChain ch versus variable v1 in TChain t1 versus variable v2 in TChain t2.

ch.Draw("var:t1.v1:t2.v2");

When a TChain::Draw is executed, an automatic call to TTree::AddFriend connects the trees in the chain. When a chain is deleted, its friend elements are also deleted.

The number of entries in the friend must be equal or greater to the number of entries of the original chain. If the friend has fewer entries a warning is given and the resulting histogram will have missing entries. For additional information see TTree::AddFriend.

Reimplemented from TTree.

Definition at line 645 of file TChain.cxx.

◆ AddFriend() [2/3]

TFriendElement * TChain::AddFriend	(	const char *	chainname,
		TFile *	dummy
	)

virtual

Add the whole chain or tree as a friend of this chain.

Reimplemented from TTree.

Definition at line 674 of file TChain.cxx.

◆ AddFriend() [3/3]

TFriendElement * TChain::AddFriend	(	TTree *	chain,
		const char *	alias = `""`,
		Bool_t	warn = `kFALSE`
	)

virtual

Add the whole chain or tree as a friend of this chain.

Reimplemented from TTree.

Definition at line 701 of file TChain.cxx.

◆ Browse()

void TChain::Browse ( TBrowser * b )

virtual

Browse the contents of the chain.

Reimplemented from TTree.

Reimplemented in TProofChain.

Definition at line 727 of file TChain.cxx.

◆ CanDeleteRefs()

void TChain::CanDeleteRefs ( Bool_t flag = kTRUE )

virtual

When closing a file during the chain processing, the file may be closed with option "R" if flag is set to kTRUE.

by default flag is kTRUE. When closing a file with option "R", all TProcessIDs referenced by this file are deleted. Calling TFile::Close("R") might be necessary in case one reads a long list of files having TRef, writing some of the referenced objects or TRef to a new file. If the TRef or referenced objects of the file being closed will not be referenced again, it is possible to minimize the size of the TProcessID data structures in memory by forcing a delete of the unused TProcessID.

Definition at line 745 of file TChain.cxx.

◆ CreatePackets()

void TChain::CreatePackets ( )

virtual

Initialize the packet descriptor string.

Definition at line 753 of file TChain.cxx.

◆ DirectoryAutoAdd()

void TChain::DirectoryAutoAdd ( TDirectory * )

virtual

Override the TTree::DirectoryAutoAdd behavior: we never auto add.

Reimplemented from TTree.

Definition at line 766 of file TChain.cxx.

◆ Draw() [1/3]

Long64_t TChain::Draw	(	const char *	varexp,
		const char *	selection,
		Option_t *	option = `""`,
		Long64_t	nentries = `kMaxEntries`,
		Long64_t	firstentry = `0`
	)

virtual

Process all entries in this chain and draw histogram corresponding to expression varexp.

Returns -1 in case of error or number of selected events in case of success.

Reimplemented from TTree.

Reimplemented in TProofChain.

Definition at line 801 of file TChain.cxx.

◆ Draw() [2/3]

Long64_t TChain::Draw	(	const char *	varexp,
		const TCut &	selection,
		Option_t *	option = `""`,
		Long64_t	nentries = `kMaxEntries`,
		Long64_t	firstentry = `0`
	)

virtual

Draw expression varexp for selected entries.

Returns -1 in case of error or number of selected events in case of success.

This function accepts TCut objects as arguments. Useful to use the string operator +, example:

ntuple.Draw("x",cut1+cut2+cut3);

Reimplemented from TTree.

Reimplemented in TProofChain.

Definition at line 781 of file TChain.cxx.

◆ Draw() [3/3]

virtual void TChain::Draw ( Option_t * option )

inlinevirtual

Default Draw method for all objects.

Reimplemented from TTree.

Reimplemented in TProofChain.

Definition at line 87 of file TChain.h.

◆ Fill()

virtual Int_t TChain::Fill ( )

inlinevirtual

Fill all branches.

This function loops on all the branches of this tree. For each branch, it copies to the branch buffer (basket) the current values of the leaves data types. If a leaf is a simple data type, a simple conversion to a machine independent format has to be done.

This machine independent version of the data is copied into a basket (each branch has its own basket). When a basket is full (32k worth of data by default), it is then optionally compressed and written to disk (this operation is also called committing or 'flushing' the basket). The committed baskets are then immediately removed from memory.

The function returns the number of bytes committed to the individual branches.

If a write error occurs, the number of bytes returned is -1.

If no data are written, because, e.g., the branch is disabled, the number of bytes returned is 0.

The baskets are flushed and the Tree header saved at regular intervals

At regular intervals, when the amount of data written so far is greater than fAutoFlush (see SetAutoFlush) all the baskets are flushed to disk. This makes future reading faster as it guarantees that baskets belonging to nearby entries will be on the same disk region. When the first call to flush the baskets happen, we also take this opportunity to optimize the baskets buffers. We also check if the amount of data written is greater than fAutoSave (see SetAutoSave). In this case we also write the Tree header. This makes the Tree recoverable up to this point in case the program writing the Tree crashes. The decisions to FlushBaskets and Auto Save can be made based either on the number of bytes written (fAutoFlush and fAutoSave negative) or on the number of entries written (fAutoFlush and fAutoSave positive). Note that the user can decide to call FlushBaskets and AutoSave in her event loop base on the number of events written instead of the number of bytes written.

Note that calling FlushBaskets too often increases the IO time.

Note that calling AutoSave too often increases the IO time and also the file size.

Reimplemented from TTree.

Definition at line 88 of file TChain.h.

◆ FindBranch()

TBranch * TChain::FindBranch ( const char * name )

virtual

See TTree::GetReadEntry().

Reimplemented from TTree.

Reimplemented in TProofChain.

Definition at line 820 of file TChain.cxx.

◆ FindLeaf()

TLeaf * TChain::FindLeaf ( const char * name )

virtual

See TTree::GetReadEntry().

Reimplemented from TTree.

Reimplemented in TProofChain.

Definition at line 841 of file TChain.cxx.

virtual Long64_t TChain::GetCacheSize ( ) const

inlinevirtual

Reimplemented from TTree.

Definition at line 93 of file TChain.h.

◆ GetChainEntryNumber()

Long64_t TChain::GetChainEntryNumber ( Long64_t entry ) const

virtual

Return absolute entry number in the chain.

The input parameter entry is the entry number in the current tree of this chain.

Reimplemented from TTree.

Definition at line 930 of file TChain.cxx.

◆ GetClusterIterator()

TTree::TClusterIterator TChain::GetClusterIterator ( Long64_t firstentry )

virtual

Return an iterator over the cluster of baskets starting at firstentry.

This iterator is not yet supported for TChain object.

Reimplemented from TTree.

Definition at line 919 of file TChain.cxx.

◆ GetEntries() [1/2]

Long64_t TChain::GetEntries ( ) const

virtual

Return the total number of entries in the chain.

In case the number of entries in each tree is not yet known, the offset table is computed.

Reimplemented from TTree.

Reimplemented in TProofChain.

Definition at line 940 of file TChain.cxx.

◆ GetEntries() [2/2]

virtual Long64_t TChain::GetEntries ( const char * selection )

inlinevirtual

Return the number of entries matching the selection.

Return -1 in case of errors.

If the selection uses any arrays or containers, we return the number of entries where at least one element match the selection. GetEntries is implemented using the selector class TSelectorEntries, which can be used directly (see code in TTreePlayer::GetEntries) for additional option. If SetEventList was used on the TTree or TChain, only that subset of entries will be considered.

Reimplemented from TTree.

Reimplemented in TProofChain.

Definition at line 98 of file TChain.h.

◆ GetEntry()

Int_t TChain::GetEntry	(	Long64_t	entry = `0`,
		Int_t	getall = `0`
	)

virtual

Get entry from the file to memory.

getall = 0 : get only active branches
getall = 1 : get all branches

Return the total number of bytes read, 0 bytes read indicates a failure.

Reimplemented from TTree.

Definition at line 964 of file TChain.cxx.

◆ GetEntryNumber()

Long64_t TChain::GetEntryNumber ( Long64_t entry ) const

virtual

Return entry number corresponding to entry.

if no TEntryList set returns entry else returns entry #entry from this entry list and also computes the global entry number (loads all tree headers)

Reimplemented from TTree.

Definition at line 983 of file TChain.cxx.

◆ GetEntryWithIndex()

Int_t TChain::GetEntryWithIndex	(	Int_t	major,
		Int_t	minor = `0`
	)

virtual

Return entry corresponding to major and minor number.

The function returns the total number of bytes read. If the Tree has friend trees, the corresponding entry with the index values (major,minor) is read. Note that the master Tree and its friend may have different entry serial numbers corresponding to (major,minor).

Reimplemented from TTree.

Definition at line 1016 of file TChain.cxx.

◆ GetFile()

TFile * TChain::GetFile ( ) const

Return a pointer to the current file.

If no file is connected, the first file is automatically loaded.

Definition at line 1027 of file TChain.cxx.

◆ GetLeaf() [1/2]

TLeaf * TChain::GetLeaf	(	const char *	branchname,
		const char *	leafname
	)

virtual

Return a pointer to the leaf name in the current tree.

Reimplemented from TTree.

Definition at line 1040 of file TChain.cxx.

◆ GetLeaf() [2/2]

TLeaf * TChain::GetLeaf ( const char * name )

virtual

Return a pointer to the leaf name in the current tree.

Reimplemented from TTree.

Definition at line 1061 of file TChain.cxx.

◆ GetListOfBranches()

TObjArray * TChain::GetListOfBranches ( )

virtual

Return a pointer to the list of branches of the current tree.

Warning: If there is no current TTree yet, this routine will open the first in the chain.

Returns 0 on failure.

Reimplemented from TTree.

Reimplemented in TProofChain.

Definition at line 1087 of file TChain.cxx.

◆ GetListOfFiles()

TObjArray * TChain::GetListOfFiles ( ) const

inline

Definition at line 108 of file TChain.h.

◆ GetListOfLeaves()

TObjArray * TChain::GetListOfLeaves ( )

virtual

Return a pointer to the list of leaves of the current tree.

Warning: May set the current tree!

Reimplemented from TTree.

Reimplemented in TProofChain.

Definition at line 1110 of file TChain.cxx.

◆ GetMaximum()

Double_t TChain::GetMaximum ( const char * columname )

virtual

Return maximum of column with name columname.

Reimplemented from TTree.

Definition at line 1131 of file TChain.cxx.

◆ GetMinimum()

Double_t TChain::GetMinimum ( const char * columname )

virtual

Return minimum of column with name columname.

Reimplemented from TTree.

Definition at line 1148 of file TChain.cxx.

◆ GetNbranches()

Int_t TChain::GetNbranches ( )

virtual

Return the number of branches of the current tree.

Warning: May set the current tree!

Reimplemented from TTree.

Definition at line 1167 of file TChain.cxx.

◆ GetNtrees()

Int_t TChain::GetNtrees ( ) const

inline

Definition at line 96 of file TChain.h.

◆ GetReadEntry()

Long64_t TChain::GetReadEntry ( ) const

virtual

Double_t TChain::GetWeight ( ) const

virtual

Return the chain weight.

By default the weight is the weight of the current tree. However, if the weight has been set in TChain::SetWeight() with the option "global", then that weight will be returned.

Warning: May set the current tree!

Reimplemented from TTree.

Definition at line 1203 of file TChain.cxx.

◆ InvalidateCurrentTree()

void TChain::InvalidateCurrentTree ( )

protected

Set the TTree to be reloaded as soon as possible.

In particular this is needed when adding a Friend.

If the tree has clones, copy them into the chain clone list so we can change their branch addresses when necessary.

This is to support the syntax:

TTree* clone = chain->GetTree()->CloneTree(0);

TTree

A TTree represents a columnar dataset.

Definition: TTree.h:72

TTree::CloneTree

virtual TTree * CloneTree(Long64_t nentries=-1, Option_t *option="")

Create a clone of this tree and copy nentries.

Definition: TTree.cxx:3078

TTree::GetTree

virtual TTree * GetTree() const

Definition: TTree.h:504

Definition at line 1232 of file TChain.cxx.

◆ LoadBaskets()

Int_t TChain::LoadBaskets ( Long64_t maxmemory )

virtual

Dummy function.

It could be implemented and load all baskets of all trees in the chain. For the time being use TChain::Merge and TTree::LoadBasket on the resulting tree.

Reimplemented from TTree.

Definition at line 1250 of file TChain.cxx.

◆ LoadTree()

Long64_t TChain::LoadTree ( Long64_t entry )

virtual

Find the tree which contains entry, and set it as the current tree.

Returns the entry number in that tree.

The input argument entry is the entry serial number in the whole chain.

In case of error, LoadTree returns a negative number:

-1: The chain is empty.
-2: The requested entry number is less than zero or too large for the chain. or too large for the large TTree.
-3: The file corresponding to the entry could not be correctly open
-4: The TChainElement corresponding to the entry is missing or the TTree is missing from the file.
-5: Internal error, please report the circumstance when this happen as a ROOT issue.
-6: An error occurred within the notify callback.

Note: This is the only routine which sets the value of fTree to a non-zero pointer.

Reimplemented from TTree.

Definition at line 1277 of file TChain.cxx.

◆ Lookup()

void TChain::Lookup ( Bool_t force = kFALSE )

Check / locate the files in the chain.

By default only the files not yet looked up are checked. Use force = kTRUE to check / re-check every file.

Definition at line 1713 of file TChain.cxx.

◆ Loop()

void TChain::Loop	(	Option_t *	option = `""`,
		Long64_t	nentries = `kMaxEntries`,
		Long64_t	firstentry = `0`
	)

virtual

Loop on nentries of this chain starting at firstentry. (NOT IMPLEMENTED)

Definition at line 1783 of file TChain.cxx.

◆ ls()

void TChain::ls ( Option_t * option = "" ) const

virtual

List the chain.

Reimplemented from TNamed.

Definition at line 1827 of file TChain.cxx.

◆ Merge() [1/4]

Long64_t TChain::Merge	(	const char *	name,
		Option_t *	option = `""`
	)

virtual

Merge all the entries in the chain into a new tree in a new file.

See important note in the following function Merge().

If the chain is expecting the input tree inside a directory, this directory is NOT created by this routine.

So in a case where we have:

TChain ch("mydir/mytree");

ch.Merge("newfile.root");

The resulting file will have not subdirectory. To recreate the directory structure do:

TFile* file = TFile::Open("newfile.root", "RECREATE");
file->mkdir("mydir")->cd();
ch.Merge(file);

Definition at line 1860 of file TChain.cxx.

◆ Merge() [2/4]

Long64_t TChain::Merge	(	TCollection *	list,
		Option_t *	option = `""`
	)

virtual

Merge all chains in the collection. (NOT IMPLEMENTED)

Reimplemented from TTree.

Definition at line 1869 of file TChain.cxx.

◆ Merge() [3/4]

Long64_t TChain::Merge	(	TCollection *	list,
		TFileMergeInfo *	info
	)

virtual

Merge all chains in the collection. (NOT IMPLEMENTED)

Reimplemented from TTree.

Definition at line 1878 of file TChain.cxx.

◆ Merge() [4/4]

Long64_t TChain::Merge	(	TFile *	file,
		Int_t	basketsize,
		Option_t *	option = `""`
	)

virtual

Merge all the entries in the chain into a new tree in the current file.

Note: The "file" parameter is not the file where the new tree will be inserted. The new tree is inserted into gDirectory, which is usually the most recently opened file, or the directory most recently cd()'d to.

If option = "C" is given, the compression level for all branches in the new Tree is set to the file compression level. By default, the compression level of all branches is the original compression level in the old trees.

If basketsize > 1000, the basket size for all branches of the new tree will be set to basketsize.

Example using the file generated in $ROOTSYS/test/Event merge two copies of Event.root

gSystem.Load("libEvent");
TChain ch("T");
ch.Add("Event1.root");
ch.Add("Event2.root");
ch.Merge("all.root");

If the chain is expecting the input tree inside a directory, this directory is NOT created by this routine.

So if you do:

TChain ch("mydir/mytree");

ch.Merge("newfile.root");

The resulting file will not have subdirectories. In order to preserve the directory structure do the following instead:

TFile* file = TFile::Open("newfile.root", "RECREATE");
file->mkdir("mydir")->cd();
ch.Merge(file);

If 'option' contains the word 'fast' the merge will be done without unzipping or unstreaming the baskets (i.e., a direct copy of the raw bytes on disk).

When 'fast' is specified, 'option' can also contains a sorting order for the baskets in the output file.

There is currently 3 supported sorting order:

SortBasketsByOffset (the default)
SortBasketsByBranch
SortBasketsByEntry

When using SortBasketsByOffset the baskets are written in the output file in the same order as in the original file (i.e. the basket are sorted on their offset in the original file; Usually this also means that the baskets are sorted on the index/number of the last entry they contain)

When using SortBasketsByBranch all the baskets of each individual branches are stored contiguously. This tends to optimize reading speed when reading a small number (1->5) of branches, since all their baskets will be clustered together instead of being spread across the file. However it might decrease the performance when reading more branches (or the full entry).

When using SortBasketsByEntry the baskets with the lowest starting entry are written first. (i.e. the baskets are sorted on the index/number of the first entry they contain). This means that on the file the baskets will be in the order in which they will be needed when reading the whole tree sequentially.

IMPORTANT Note 1: AUTOMATIC FILE OVERFLOW

When merging many files, it may happen that the resulting file reaches a size > TTree::fgMaxTreeSize (default = 100 GBytes). In this case the current file is automatically closed and a new file started. If the name of the merged file was "merged.root", the subsequent files will be named "merged_1.root", "merged_2.root", etc. fgMaxTreeSize may be modified via the static function TTree::SetMaxTreeSize. When in fast mode, the check and switch is only done in between each input file.

IMPORTANT Note 2: The output file is automatically closed and deleted.

This is required because in general the automatic file overflow described above may happen during the merge. If only the current file is produced (the file passed as first argument), one can instruct Merge to not close and delete the file by specifying the option "keep".

The function returns the total number of files produced. To check that all files have been merged use something like:

if (newchain->GetEntries()!=oldchain->GetEntries()) {
   ... not all the file have been copied ...
}

Definition at line 1986 of file TChain.cxx.

◆ operator=()

TChain & TChain::operator= ( const TChain & )

private

◆ ParseTreeFilename()

void TChain::ParseTreeFilename	(	const char *	name,
		TString &	filename,
		TString &	treename,
		TString &	query,
		TString &	suffix,
		Bool_t	wildcards
	)		const

private

Get the tree url or filename and other information from the name.

A treename and a url's query section is split off from name. The splitting depends on whether the resulting filename is to be subsequently treated for wildcards or not, since the question mark is both the url query identifier and a wildcard. Wildcard matching is not done in this method itself.

[xxx://host]/a/path/file_name[?query[#treename]]

The following way to specify the treename is still supported with the constrain that the file name contains the sub-string '.root'. This is now deprecated and will be removed in future versions.

[xxx://host]/a/path/file.root[.oext][/treename]

[xxx://host]/a/path/file.root[.oext][/treename][?query]

Note that in a case like this

[xxx://host]/a/path/file#treename

i.e. anchor but no options (query), the filename will be the full path, as the anchor may be the internal file name of an archive. Use '?#treename' to pass the treename if the query field is empty.

Parameters

[in]	name	is the original name
[in]	wildcards	indicates if the resulting filename will be treated for wildcards. For backwards compatibility, with most protocols this flag suppresses the search for the url fragment identifier and limits the query identifier search to cases where the tree name is given as a trailing slash-separated string at the end of the file name.
[out]	filename	the url or filename to be opened or matched
[out]	treename	the treename, which may be found in a url fragment section as a trailing part of the name (deprecated). If not found this will be empty.
[out]	query	is the url query section, including the leading question mark. If not found or the query section is only followed by a fragment this will be empty.
[out]	suffix	the portion of name which was removed to from filename.

Definition at line 2129 of file TChain.cxx.

void TChain::RecursiveRemove ( TObject * obj )

virtual

Make sure that obj (which is being deleted or will soon be) is no longer referenced by this TTree.

void TChain::SavePrimitive	(	std::ostream &	out,
		Option_t *	option = `""`
	)

virtual

Save TChain as a C++ statements on output stream out.

With the option "friend" save the description of all the TChain's friend trees or chains as well.

Reimplemented from TObject.

Definition at line 2334 of file TChain.cxx.

◆ Scan()

Long64_t TChain::Scan	(	const char *	varexp = `""`,
		const char *	selection = `""`,
		Option_t *	option = `""`,
		Long64_t	nentries = `kMaxEntries`,
		Long64_t	firstentry = `0`
	)

virtual

Loop on tree and print entries passing selection.

If varexp is 0 (or "") then print only first 8 columns.
If varexp = "*" print all columns.
Otherwise a columns selection can be made using "var1:var2:var3". See TTreePlayer::Scan for more information.

Reimplemented from TTree.

Definition at line 2403 of file TChain.cxx.

◆ SetAutoDelete()

void TChain::SetAutoDelete ( Bool_t autodelete = kTRUE )

virtual

Set the global branch kAutoDelete bit.

When LoadTree loads a new Tree, the branches for which the address is set will have the option AutoDelete set For more details on AutoDelete, see TBranch::SetAutoDelete.

Definition at line 2418 of file TChain.cxx.

◆ SetBranchAddress() [1/5]

template<class T >

Int_t TChain::SetBranchAddress	(	const char *	bname,
		T **	add,
		TBranch **	ptr = `0`
	)

inline

Definition at line 145 of file TChain.h.

◆ SetBranchAddress() [2/5]

template<class T >

Int_t TChain::SetBranchAddress	(	const char *	bname,
		T *	add,
		TBranch **	ptr = `0`
	)

inline

Definition at line 151 of file TChain.h.

◆ SetBranchAddress() [3/5]

Int_t TChain::SetBranchAddress	(	const char *	bname,
		void *	add,
		TBranch **	ptr,
		TClass *	realClass,
		EDataType	datatype,
		Bool_t	isptr
	)

virtual

Check if bname is already in the status list, and if not, create a TChainElement object and set its address.

See TTree::CheckBranchAddressType for the semantic of the return value.

Note: See the comments in TBranchElement::SetAddress() for a more detailed discussion of the meaning of the add parameter.

Reimplemented from TTree.

Definition at line 2569 of file TChain.cxx.

◆ SetBranchAddress() [4/5]

Int_t TChain::SetBranchAddress	(	const char *	bname,
		void *	add,
		TBranch **	ptr = `0`
	)

virtual

Set branch address.

Parameters

[in]	bname	is the name of a branch.
[in]	add	is the address of the branch.
[in]	ptr

Note: See the comments in TBranchElement::SetAddress() for a more detailed discussion of the meaning of the add parameter.

IMPORTANT REMARK:

In case TChain::SetBranchStatus is called, it must be called BEFORE calling this function.

See TTree::CheckBranchAddressType for the semantic of the return value.

Reimplemented from TTree.

Definition at line 2495 of file TChain.cxx.

◆ SetBranchAddress() [5/5]

Int_t TChain::SetBranchAddress	(	const char *	bname,
		void *	add,
		TClass *	realClass,
		EDataType	datatype,
		Bool_t	isptr
	)

virtual

Check if bname is already in the status list, and if not, create a TChainElement object and set its address.

See TTree::CheckBranchAddressType for the semantic of the return value.

Note: See the comments in TBranchElement::SetAddress() for a more detailed discussion of the meaning of the add parameter.

Reimplemented from TTree.

Definition at line 2557 of file TChain.cxx.

◆ SetBranchStatus()

void TChain::SetBranchStatus	(	const char *	bname,
		Bool_t	status = `1`,
		UInt_t *	found = `0`
	)

virtual

Set branch status to Process or DoNotProcess.

Parameters

[in]	bname	is the name of a branch. if bname="*", apply to all branches.
[in]	status	= 1 branch will be processed, = 0 branch will not be processed
[out]	found

See IMPORTANT REMARKS in TTree::SetBranchStatus and TChain::SetBranchAddress

If found is not 0, the number of branch(es) found matching the regular expression is returned in *found AND the error message 'unknown branch' is suppressed.

Reimplemented from TTree.

Definition at line 2599 of file TChain.cxx.

◆ SetCacheSize()

Int_t TChain::SetCacheSize ( Long64_t cacheSize = -1 )

virtual

Set maximum size of the file cache .

if cachesize = 0 the existing cache (if any) is deleted.
if cachesize = -1 (default) it is set to the AutoFlush value when writing the Tree (default is 30 MBytes).

Returns:

0 size set, cache was created if possible
-1 on error

Reimplemented from TTree.

Definition at line 2427 of file TChain.cxx.

◆ SetDirectory()

void TChain::SetDirectory ( TDirectory * dir )

virtual

Remove reference to this chain from current directory and add reference to new directory dir.

dir can be 0 in which case the chain does not belong to any directory.

Reimplemented from TTree.

Definition at line 2626 of file TChain.cxx.

◆ SetEntryList()

void TChain::SetEntryList	(	TEntryList *	elist,
		Option_t *	opt = `""`
	)

virtual

Set the input entry list (processing the entries of the chain will then be limited to the entries in the list).

This function finds correspondence between the sub-lists of the TEntryList and the trees of the TChain. By default (opt=""), both the file names of the chain elements and the file names of the TEntryList sublists are expanded to full path name. If opt = "ne", the file names are taken as they are and not expanded

Reimplemented from TTree.

Definition at line 2648 of file TChain.cxx.

◆ SetEntryListFile()

void TChain::SetEntryListFile	(	const char *	filename = `""`,
		Option_t *	opt = `""`
	)

virtual

Set the input entry list (processing the entries of the chain will then be limited to the entries in the list).

This function creates a special kind of entry list (TEntryListFromFile object) that loads lists, corresponding to the chain elements, one by one, so that only one list is in memory at a time.

If there is an error opening one of the files, this file is skipped and the next file is loaded

File naming convention:

by default, filename_elist.root is used, where filename is the name of the chain element
xxx$xxx.root - $ sign is replaced by the name of the chain element

If the list name is not specified (by passing filename_elist.root/listname to the TChain::SetEntryList() function, the first object of class TEntryList in the file is taken.

It is assumed, that there are as many list files, as there are elements in the chain and they are in the same order

Definition at line 2743 of file TChain.cxx.

◆ SetEventList()

void TChain::SetEventList ( TEventList * evlist )

virtual

This function transfroms the given TEventList into a TEntryList.

NOTE, that this function loads all tree headers, because the entry numbers in the TEventList are global and have to be recomputed, taking into account the number of entries in each tree.

The new TEntryList is owned by the TChain and gets deleted when the chain is deleted. This TEntryList is returned by GetEntryList() function, and after GetEntryList() function is called, the TEntryList is not owned by the chain any more and will not be deleted with it.

Reimplemented from TTree.

Reimplemented in TProofChain.

Definition at line 2789 of file TChain.cxx.

◆ SetMakeClass()

virtual void TChain::SetMakeClass ( Int_t make )

inlinevirtual

Set all the branches in this TTree to be in decomposed object mode (also known as MakeClass mode).

For MakeClass mode 0, the TTree expects the address where the data is stored to be set by either the user or the TTree to the address of a full object through the top level branch. For MakeClass mode 1, this address is expected to point to a numerical type or C-style array (variable or not) of numerical type, representing the primitive data members. The function's primary purpose is to allow the user to access the data directly with numerical type variable rather than having to have the original set of classes (or a reproduction thereof).

Reimplemented from TTree.

Definition at line 162 of file TChain.h.

◆ SetName()

void TChain::SetName ( const char * name )

virtual

Change the name of this TChain.

Reimplemented from TTree.

Reimplemented in TProofChain.

Definition at line 2864 of file TChain.cxx.

◆ SetPacketSize()

void TChain::SetPacketSize ( Int_t size = 100 )

virtual

Set number of entries per packet for parallel root.

Definition at line 2887 of file TChain.cxx.

◆ SetProof()

void TChain::SetProof	(	Bool_t	on = `kTRUE`,
		Bool_t	refresh = `kFALSE`,
		Bool_t	gettreeheader = `kFALSE`
	)

virtual

Enable/Disable PROOF processing on the current default Proof (gProof).

"Draw" and "Processed" commands will be handled by PROOF. The refresh and gettreeheader are meaningful only if on == kTRUE. If refresh is kTRUE the underlying fProofChain (chain proxy) is always rebuilt (even if already existing). If gettreeheader is kTRUE the header of the tree will be read from the PROOF cluster: this is only needed for browsing and should be used with care because it may take a long time to execute.

Definition at line 2908 of file TChain.cxx.

◆ SetWeight()

void TChain::SetWeight	(	Double_t	w = `1`,
		Option_t *	option = `""`
	)

virtual

Set chain weight.

The weight is used by TTree::Draw to automatically weight each selected entry in the resulting histogram. For example the equivalent of

chain.Draw("x","w")

is

chain.SetWeight(w,"global");

chain.Draw("x");

By default the weight used will be the weight of each Tree in the TChain. However, one can force the individual weights to be ignored by specifying the option "global". In this case, the TChain global weight will be used for all Trees.

Reimplemented from TTree.

Definition at line 2955 of file TChain.cxx.

◆ UseCache()

void TChain::UseCache	(	Int_t	maxCacheSize = `10`,
		Int_t	pageSize = `0`
	)

virtual

Int_t TChain::fTreeOffsetLen

protected

Current size of fTreeOffset array.

Definition at line 37 of file TChain.h.

◆ kBigNumber

constexpr auto TChain::kBigNumber = TTree::kMaxEntries

staticconstexpr

Definition at line 67 of file TChain.h.

Libraries for TChain:

[legend]

Public Types

Public Member Functions

Static Public Attributes

Protected Member Functions

Protected Attributes

Private Member Functions

Additional Inherited Members

Member Enumeration Documentation

◆ EStatusBits

Constructor & Destructor Documentation

◆ TChain() [1/3]

◆ TChain() [2/3]

◆ TChain() [3/3]

◆ ~TChain()

Member Function Documentation

◆ Add() [1/2]

◆ Add() [2/2]

◆ AddFile()

◆ AddFileInfoList()

◆ AddFriend() [1/3]

◆ AddFriend() [2/3]

◆ AddFriend() [3/3]

◆ Browse()

◆ CanDeleteRefs()

◆ CreatePackets()

◆ DirectoryAutoAdd()

◆ Draw() [1/3]

◆ Draw() [2/3]

◆ Draw() [3/3]

◆ Fill()

◆ FindBranch()

◆ FindLeaf()

◆ GetAlias()

◆ GetBranch()

◆ GetBranchStatus()

◆ GetCacheSize()

◆ GetChainEntryNumber()

◆ GetClusterIterator()

◆ GetEntries() [1/2]

◆ GetEntries() [2/2]

◆ GetEntry()

◆ GetEntryNumber()

◆ GetEntryWithIndex()

◆ GetFile()

◆ GetLeaf() [1/2]

◆ GetLeaf() [2/2]

◆ GetListOfBranches()

◆ GetListOfFiles()

◆ GetListOfLeaves()

◆ GetMaximum()

◆ GetMinimum()

◆ GetNbranches()

◆ GetNtrees()

◆ GetReadEntry()

◆ GetStatus()

◆ GetTree()

◆ GetTreeNumber()

◆ GetTreeOffset()

◆ GetTreeOffsetLen()

◆ GetWeight()

◆ InvalidateCurrentTree()

◆ LoadBaskets()

◆ LoadTree()

◆ Lookup()

◆ Loop()

◆ ls()

◆ Merge() [1/4]

◆ Merge() [2/4]

◆ Merge() [3/4]

◆ Merge() [4/4]

IMPORTANT Note 1: AUTOMATIC FILE OVERFLOW

IMPORTANT Note 2: The output file is automatically closed and deleted.

◆ operator=()

◆ ParseTreeFilename()

◆ Print()

◆ Process() [1/2]

◆ Process() [2/2]

◆ RecursiveRemove()

◆ ReleaseChainProof()

◆ RemoveFriend()