Efficient multidimensional histogram.

Use a THnSparse instead of TH1 / TH2 / TH3 / array for histogramming when only a small fraction of bins is filled. A 10-dimensional histogram with 10 bins per dimension has 10^10 bins; in a naive implementation this will not fit in memory. THnSparse only allocates memory for the bins that have non-zero bin content instead, drastically reducing both the memory usage and the access time.

To construct a THnSparse object you must use one of its templated, derived classes:

THnSparseD (typedef for THnSparseT<ArrayD>): bin content held by a Double_t,
THnSparseF (typedef for THnSparseT<ArrayF>): bin content held by a Float_t,
THnSparseL (typedef for THnSparseT<ArrayL>): bin content held by a Long_t,
THnSparseI (typedef for THnSparseT<ArrayI>): bin content held by an Int_t,
THnSparseS (typedef for THnSparseT<ArrayS>): bin content held by a Short_t,
THnSparseC (typedef for THnSparseT<ArrayC>): bin content held by a Char_t,

They take name and title, the number of dimensions, and for each dimension the number of bins, the minimal, and the maximal value on the dimension's axis. A TH2 h("h","h",10, 0., 10., 20, -5., 5.) would correspond to

Int_t bins[2] = {10, 20};
Double_t xmin[2] = {0., -5.};
Double_t xmax[2] = {10., 5.};
THnSparse hs("hs", "hs", 2, bins, min, max);

Filling

A THnSparse is filled just like a regular histogram, using THnSparse::Fill(x, weight), where x is a n-dimensional Double_t value. To take errors into account, Sumw2() must be called before filling the histogram.

Bins are allocated as needed; the status of the allocation can be observed by GetSparseFractionBins(), GetSparseFractionMem().

Fast Bin Content Access

When iterating over a THnSparse one should only look at filled bins to save processing time. The number of filled bins is returned by THnSparse::GetNbins(); the bin content for each (linear) bin number can be retrieved by THnSparse::GetBinContent(linidx, (Int_t*)coord). After the call, coord will contain the bin coordinate of each axis for the bin with linear index linidx. A possible call would be

std::cout << hs.GetBinContent(0, coord); std::cout <<" is the content of bin [x = " << coord[0] " << " | y = " << coord[1] << "]" << std::endl;

Efficiency

TH1 and TH2 are generally faster than THnSparse for one and two dimensional distributions. THnSparse becomes competitive for a sparsely filled TH3 with large numbers of bins per dimension. The tutorial sparsehist.C shows the turning point. On a AMD64 with 8GB memory, THnSparse "wins" starting with a TH3 with 30 bins per dimension. Using a THnSparse for a one-dimensional histogram is only reasonable if it has a huge number of bins.

Projections

The dimensionality of a THnSparse can be reduced by projecting it to 1, 2, 3, or n dimensions, which can be represented by a TH1, TH2, TH3, or a THnSparse. See the Projection() members. To only project parts of the histogram, call

THnSparse::GetAxis(12)->SetRange(from_bin, to_bin);

Internal Representation

An entry for a filled bin consists of its n-dimensional coordinates and its bin content. The coordinates are compacted to use as few bits as possible; e.g. a histogram with 10 bins in x and 20 bins in y will only use 4 bits for the x representation and 5 bits for the y representation. This is handled by the internal class THnSparseCompactBinCoord. Bin data (content and coordinates) are allocated in chunks of size fChunkSize; this parameter can be set when constructing a THnSparse. Each chunk is represented by an object of class THnSparseArrayChunk.

Translation from an n-dimensional bin coordinate to the linear index within the chunks is done by GetBin(). It creates a hash from the compacted bin coordinates (the hash of a bin coordinate is the compacted coordinate itself if it takes less than 8 bytes, the size of a Long64_t. This hash is used to lookup the linear index in the TExMap member fBins; the coordinates of the entry fBins points to is compared to the coordinates passed to GetBin(). If they do not match, these two coordinates have the same hash - which is extremely unlikely but (for the case where the compact bin coordinates are larger than 4 bytes) possible. In this case, fBinsContinued contains a chain of linear indexes with the same hash. Iterating through this chain and comparing each bin coordinates with the one passed to GetBin() will retrieve the matching bin.

Definition at line 36 of file THnSparse.h.

Public Member Functions
virtual	~THnSparse ()
	Destruct a THnSparse. More...

void	AddBinContent (const Int_t *idx, Double_t v=1.)

void	AddBinContent (Long64_t bin, Double_t v=1.)
	Add "v" to the content of bin with index "bin". More...

void	AddBinError2 (Long64_t bin, Double_t e2)
	Add "e" to error of bin with index "bin", enable errors if needed. More...

ROOT::Internal::THnBaseBinIter *	CreateIter (Bool_t respectAxisRange) const
	Create an iterator over all filled bins of a THnSparse. More...

Long64_t	GetBin (const Int_t *idx) const

Long64_t	GetBin (const Double_t *x) const

Long64_t	GetBin (const char *name[]) const

Long64_t	GetBin (const Int_t *idx, Bool_t allocate=kTRUE)
	Get the bin index for the n dimensional coordinates coord, allocate one if it doesn't exist yet and "allocate" is true. More...

Long64_t	GetBin (const Double_t *x, Bool_t allocate=kTRUE)
	Get the bin index for the n dimensional tuple x, allocate one if it doesn't exist yet and "allocate" is true. More...

Long64_t	GetBin (const char *name[], Bool_t allocate=kTRUE)
	Get the bin index for the n dimensional tuple addressed by "name", allocate one if it doesn't exist yet and "allocate" is true. More...

Double_t	GetBinContent (const Int_t *idx) const

Double_t	GetBinContent (Long64_t bin, Int_t *idx=0) const
	Return the content of the filled bin number "idx". More...

Double_t	GetBinError2 (Long64_t linidx) const
	Get square of the error of bin addressed by linidx as \(\sum weight^{2}\) If errors are not enabled (via Sumw2() or CalculateErrors()) return contents. More...

Int_t	GetChunkSize () const

Long64_t	GetNbins () const

Int_t	GetNChunks () const

Double_t	GetSparseFractionBins () const
	Return the amount of filled bins over all bins. More...

Double_t	GetSparseFractionMem () const
	Return the amount of used memory over memory that would be used by a non-sparse n-dimensional histogram. More...

TH1D *	Projection (Int_t xDim, Option_t *option="") const

TH2D *	Projection (Int_t yDim, Int_t xDim, Option_t *option="") const

TH3D *	Projection (Int_t xDim, Int_t yDim, Int_t zDim, Option_t *option="") const

THnSparse *	Projection (Int_t ndim, const Int_t dim, Option_t option="") const

THnSparse *	Rebin (Int_t group) const

THnSparse *	Rebin (const Int_t *group) const

void	Reset (Option_t *option="")
	Clear the histogram. More...

void	SetBinContent (const Int_t *idx, Double_t v)

void	SetBinContent (Long64_t bin, Double_t v)
	Set content of bin with index "bin" to "v". More...

void	SetBinError2 (Long64_t bin, Double_t e2)
	Set error of bin with index "bin" to "e", enable errors if needed. More...

void	SetFilledBins (Long64_t nbins)

void	Sumw2 ()
	Enable calculation of errors. More...

Public Member Functions inherited from THnBase
virtual	~THnBase ()
	Destruct a THnBase. More...

void	Add (const THnBase *h, Double_t c=1.)
	Add contents of h scaled by c to this histogram: this = this + c * h Note that if h has Sumw2 set, Sumw2 is automatically called for this if not already set. More...

void	Add (const TH1 *hist, Double_t c=1.)
	Fill the THnBase with the bins of hist that have content or error != 0. More...

void	AddBinContent (const Int_t *x, Double_t v=1.)

void	Browse (TBrowser *b)
	Browse a THnSparse: create an entry (ROOT::THnSparseBrowsable) for each dimension. More...

void	CalculateErrors (Bool_t calc=kTRUE)

Double_t	ComputeIntegral ()
	Calculate the integral of the histogram. More...

void	Divide (const THnBase *h)
	Divide this histogram by h this = this/(h) Note that if h has Sumw2 set, Sumw2 is automatically called for this if not already set. More...

void	Divide (const THnBase h1, const THnBase h2, Double_t c1=1., Double_t c2=1., Option_t *option="")
	Replace contents of this histogram by multiplication of h1 by h2 this = (c1h1)/(c2h2) Note that if h1 or h2 have Sumw2 set, Sumw2 is automatically called for this if not already set. More...

Long64_t	Fill (const Double_t *x, Double_t w=1.)

Long64_t	Fill (const char *name[], Double_t w=1.)

TFitResultPtr	Fit (TF1 f1, Option_t option="", Option_t *goption="")
	Fit a THnSparse with function f. More...

TAxis *	GetAxis (Int_t dim) const

Double_t	GetBinContent (const Int_t *idx) const

Double_t	GetBinError (const Int_t *idx) const

Double_t	GetBinError (Long64_t linidx) const

Bool_t	GetCalculateErrors () const

Double_t	GetEntries () const

TObjArray *	GetListOfAxes ()

const TObjArray *	GetListOfAxes () const

TList *	GetListOfFunctions ()

Int_t	GetNdimensions () const

void	GetRandom (Double_t *rand, Bool_t subBinRandom=kTRUE)
	Generate an n-dimensional random tuple based on the histogrammed distribution. More...

Double_t	GetSumw () const

Double_t	GetSumw2 () const

Double_t	GetSumwx (Int_t dim) const

Double_t	GetSumwx2 (Int_t dim) const

Double_t	GetWeightSum () const

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

Bool_t	IsInRange (Int_t *coord) const
	Check whether bin coord is in range, as defined by TAxis::SetRange(). More...

Long64_t	Merge (TCollection *list)
	Merge this with a list of THnBase's. More...

void	Multiply (const THnBase *h)
	Multiply this histogram by histogram h this = this * h Note that if h has Sumw2 set, Sumw2 is automatically called for this if not already set. More...

void	Multiply (TF1 *f, Double_t c=1.)
	Performs the operation: this = thiscf1 if errors are defined, errors are also recalculated. More...

void	Print (Option_t *option="") const
	Print a THnBase. More...

void	PrintBin (Int_t coord, Option_t options) const

void	PrintBin (Long64_t idx, Option_t *options) const
	Print bin with linex index "idx". More...

void	PrintEntries (Long64_t from=0, Long64_t howmany=-1, Option_t *options=0) const
	Print "howmany" entries starting at "from". More...

TH1D *	Projection (Int_t xDim, Option_t *option="") const

TH2D *	Projection (Int_t yDim, Int_t xDim, Option_t *option="") const

TH3D *	Projection (Int_t xDim, Int_t yDim, Int_t zDim, Option_t *option="") const

THnBase *	ProjectionND (Int_t ndim, const Int_t dim, Option_t option="") const

void	RebinnedAdd (const THnBase *h, Double_t c=1.)
	Add contents of h scaled by c to this histogram: this = this + c * h Note that if h has Sumw2 set, Sumw2 is automatically called for this if not already set. More...

void	Scale (Double_t c)
	Scale contents and errors of this histogram by c: this = this * c It does not modify the histogram's number of entries. More...

void	SetBinContent (const Int_t *idx, Double_t v)

void	SetBinEdges (Int_t idim, const Double_t *bins)
	Set the axis # of bins and bin limits on dimension idim. More...

void	SetBinError (const Int_t *idx, Double_t e)

void	SetBinError (Long64_t bin, Double_t e)

void	SetEntries (Double_t entries)

void	SetTitle (const char *title)
	Change (i.e. More...

Public Member Functions inherited from TNamed
	TNamed ()

	TNamed (const char name, const char title)

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

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

virtual	~TNamed ()

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

Bool_t	IsOnHeap () const

Bool_t	IsZombie () const

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

void	SetBit (UInt_t f)

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...

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...

Static Public Member Functions
static THnSparse *	CreateSparse (const char name, const char title, const TH1 h1, Int_t chunkSize=1024 16)

static THnSparse *	CreateSparse (const char name, const char title, const THnBase hn, Int_t chunkSize=1024 16)

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 Member Functions
	THnSparse ()
	Construct an empty THnSparse. More...

	THnSparse (const char name, const char title, Int_t dim, const Int_t nbins, const Double_t xmin, const Double_t *xmax, Int_t chunksize)
	Construct a THnSparse with "dim" dimensions, with chunksize as the size of the chunks. More...

THnSparseArrayChunk *	AddChunk ()
	Create a new chunk of bin content. More...

void	FillBin (Long64_t bin, Double_t w)

void	FillExMap ()
	We have been streamed; set up fBins. More...

virtual TArray *	GenerateArray () const =0

Long64_t	GetBinIndexForCurrentBin (Bool_t allocate)
	Return the index for fCurrentBinIndex. More...

THnSparseArrayChunk *	GetChunk (Int_t idx) const

THnSparseCompactBinCoord *	GetCompactCoord () const
	Return THnSparseCompactBinCoord object. More...

void	InitStorage (Int_t *nbins, Int_t chunkSize)
	Initialize the storage of a histogram created via Init() More...

void	Reserve (Long64_t nbins)
	Initialize storage for nbins. More...

Protected Member Functions inherited from THnBase
	THnBase ()

	THnBase (const char name, const char title, Int_t dim, const Int_t nbins, const Double_t xmin, const Double_t *xmax)
	Construct a THnBase with "dim" dimensions, "nbins" holds the number of bins for each dimension; "xmin" and "xmax" the minimal and maximal value for each dimension. More...

void	AddInternal (const THnBase *h, Double_t c, Bool_t rebinned)
	Add() implementation for both rebinned histograms and those with identical binning. More...

Bool_t	CheckConsistency (const THnBase h, const char tag) const
	Consistency check on (some of) the parameters of two histograms (for operations). More...

THnBase *	CloneEmpty (const char name, const char title, const TObjArray *axes, Bool_t keepTargetAxis) const
	Create a new THnBase object that is of the same type as *this, but with dimensions and bins given by axes. More...

TH1 *	CreateHist (const char name, const char title, const TObjArray *axes, Bool_t keepTargetAxis) const
	Create an empty histogram with name and title with a given set of axes. More...

void	FillBinBase (Double_t w)

void	Init (const char name, const char title, const TObjArray axes, Bool_t keepTargetAxis, Int_t chunkSize=1024 16)
	Initialize axes and name. More...

Bool_t	PrintBin (Long64_t idx, Int_t coord, Option_t options) const
	Print one bin. More...

TObject *	ProjectionAny (Int_t ndim, const Int_t dim, Bool_t wantNDim, Option_t option="") const
	Project all bins into a ndim-dimensional THn / THnSparse (whatever *this is) or if (ndim < 4 and !wantNDim) a TH1/2/3 histogram, keeping only axes in dim (specifying ndim dimensions). More...

THnBase *	RebinBase (Int_t group) const
	Combine the content of "group" neighboring bins into a new bin and return the resulting THnBase. More...

THnBase *	RebinBase (const Int_t *group) const
	Combine the content of "group" neighboring bins for each dimension into a new bin and return the resulting THnBase. More...

void	ResetBase (Option_t *option="")
	Clear the histogram. More...

void	UpdateXStat (const Double_t *x, Double_t w=1.)

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 ()

Private Member Functions
	THnSparse (const THnSparse &)
	compact coordinate More...

THnSparse &	operator= (const THnSparse &)

Private Attributes
TObjArray	fBinContent

TExMap	fBins

TExMap	fBinsContinued
	filled bins More...

Int_t	fChunkSize

THnSparseCompactBinCoord *	fCompactCoord
	filled bins for non-unique hashes, containing pairs of (bin index 0, bin index 1) More...

Long64_t	fFilledBins

Additional Inherited Members
Public Types inherited from TObject
enum	{ kIsOnHeap = 0x01000000, kNotDeleted = 0x02000000, kZombie = 0x04000000, kBitMask = 0x00ffffff }

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

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

Protected Types inherited from THnBase
enum	{ kNoInt, kValidInt, kInvalidInt }
	array with bin weight sums More...

Static Protected Member Functions inherited from THnBase
static THnBase *	CreateHnAny (const char name, const char title, const TH1 h1, Bool_t sparse, Int_t chunkSize=1024 16)
	Create a THn / THnSparse object from a histogram deriving from TH1. More...

static THnBase *	CreateHnAny (const char name, const char title, const THnBase hn, Bool_t sparse, Int_t chunkSize=1024 16)
	Create a THnSparse (if "sparse") or THn from "hn", possibly converting THn <-> THnSparse. More...

Protected Attributes inherited from THnBase
TObjArray	fAxes

TObjArray	fBrowsables

Double_t	fEntries
	browser-helpers for each axis More...

Double_t *	fIntegral

enum THnBase:: { ... }	fIntegralStatus
	array with bin weight sums More...

Int_t	fNdimensions

Double_t	fTsumw

Double_t	fTsumw2

TArrayD	fTsumwx

TArrayD	fTsumwx2

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

#include <THnSparse.h>

Inheritance diagram for THnSparse:

[legend]

Constructor & Destructor Documentation

◆ THnSparse() [1/3]

THnSparse::THnSparse ( const THnSparse & )

private

compact coordinate

◆ THnSparse() [2/3]

THnSparse::THnSparse ( )

protected

Construct an empty THnSparse.

Definition at line 590 of file THnSparse.cxx.

◆ THnSparse() [3/3]

THnSparse::THnSparse	(	const char *	name,
		const char *	title,
		Int_t	dim,
		const Int_t *	nbins,
		const Double_t *	xmin,
		const Double_t *	xmax,
		Int_t	chunksize
	)

protected

Construct a THnSparse with "dim" dimensions, with chunksize as the size of the chunks.

"nbins" holds the number of bins for each dimension; "xmin" and "xmax" the minimal and maximal value for each dimension. The arrays "xmin" and "xmax" can be NULL; in that case SetBinEdges() must be called for each dimension.

Definition at line 604 of file THnSparse.cxx.

◆ ~THnSparse()

THnSparse::~THnSparse ( )

virtual

Destruct a THnSparse.

Definition at line 617 of file THnSparse.cxx.

Member Function Documentation

◆ AddBinContent() [1/2]

void THnSparse::AddBinContent	(	const Int_t *	idx,
		Double_t	v = `1.`
	)

inline

Definition at line 108 of file THnSparse.h.

◆ AddBinContent() [2/2]

void THnSparse::AddBinContent	(	Long64_t	bin,
		Double_t	v = `1.`
	)

virtual

Add "v" to the content of bin with index "bin".

Implements THnBase.

Definition at line 624 of file THnSparse.cxx.

◆ AddBinError2()

void THnSparse::AddBinError2	(	Long64_t	bin,
		Double_t	e2
	)

virtual

Add "e" to error of bin with index "bin", enable errors if needed.

Implements THnBase.

Definition at line 932 of file THnSparse.cxx.

◆ AddChunk()

THnSparseArrayChunk * THnSparse::AddChunk ( )

protected

Create a new chunk of bin content.

Definition at line 635 of file THnSparse.cxx.

◆ CreateIter()

ROOT::Internal::THnBaseBinIter * THnSparse::CreateIter ( Bool_t respectAxisRange ) const

virtual

Create an iterator over all filled bins of a THnSparse.

Use THnIter instead.

Implements THnBase.

Definition at line 897 of file THnSparse.cxx.

◆ CreateSparse() [1/2]

static THnSparse* THnSparse::CreateSparse	(	const char *	name,
		const char *	title,
		const TH1 *	h1,
		Int_t	chunkSize = `1024 * 16`
	)

inlinestatic

Definition at line 75 of file THnSparse.h.

◆ CreateSparse() [2/2]

static THnSparse* THnSparse::CreateSparse	(	const char *	name,
		const char *	title,
		const THnBase *	hn,
		Int_t	chunkSize = `1024 * 16`
	)

inlinestatic

Definition at line 80 of file THnSparse.h.

◆ FillBin()

void THnSparse::FillBin	(	Long64_t	bin,
		Double_t	w
	)

inlineprotectedvirtual

Implements THnBase.

Definition at line 63 of file THnSparse.h.

◆ FillExMap()

void THnSparse::FillExMap ( )

protected

We have been streamed; set up fBins.

Definition at line 656 of file THnSparse.cxx.

◆ GenerateArray()

virtual TArray* THnSparse::GenerateArray ( ) const

protectedpure virtual

Implemented in THnSparseT< CONT >.

◆ GetBin() [1/6]

Long64_t THnSparse::GetBin ( const Int_t * idx ) const

inlinevirtual

Implements THnBase.

Definition at line 94 of file THnSparse.h.

◆ GetBin() [2/6]

Long64_t THnSparse::GetBin ( const Double_t * x ) const

inlinevirtual

Implements THnBase.

Definition at line 95 of file THnSparse.h.

◆ GetBin() [3/6]

Long64_t THnSparse::GetBin ( const char * name[] ) const

inlinevirtual

Implements THnBase.

Definition at line 96 of file THnSparse.h.

◆ GetBin() [4/6]

Long64_t THnSparse::GetBin	(	const Int_t *	coord,
		Bool_t	allocate = `kTRUE`
	)

virtual

Get the bin index for the n dimensional coordinates coord, allocate one if it doesn't exist yet and "allocate" is true.

Implements THnBase.

Definition at line 734 of file THnSparse.cxx.

◆ GetBin() [5/6]

Long64_t THnSparse::GetBin	(	const Double_t *	x,
		Bool_t	allocate = `kTRUE`
	)

virtual

Get the bin index for the n dimensional tuple x, allocate one if it doesn't exist yet and "allocate" is true.

Implements THnBase.

Definition at line 703 of file THnSparse.cxx.

◆ GetBin() [6/6]

Long64_t THnSparse::GetBin	(	const char *	name[],
		Bool_t	allocate = `kTRUE`
	)

virtual

Get the bin index for the n dimensional tuple addressed by "name", allocate one if it doesn't exist yet and "allocate" is true.

Implements THnBase.

Definition at line 719 of file THnSparse.cxx.

◆ GetBinContent() [1/2]

Double_t THnSparse::GetBinContent ( const Int_t * idx ) const

inline

Definition at line 116 of file THnSparse.h.

◆ GetBinContent() [2/2]

Double_t THnSparse::GetBinContent	(	Long64_t	idx,
		Int_t *	coord = `0`
	)		const

virtual

Return the content of the filled bin number "idx".

If coord is non-null, it will contain the bin's coordinates for each axis that correspond to the bin.

Implements THnBase.

Definition at line 745 of file THnSparse.cxx.

◆ GetBinError2()

Double_t THnSparse::GetBinError2 ( Long64_t linidx ) const

virtual

Get square of the error of bin addressed by linidx as \(\sum weight^{2}\) If errors are not enabled (via Sumw2() or CalculateErrors()) return contents.

Implements THnBase.

Definition at line 772 of file THnSparse.cxx.

◆ GetBinIndexForCurrentBin()

Long64_t THnSparse::GetBinIndexForCurrentBin ( Bool_t allocate )

protected

Return the index for fCurrentBinIndex.

If it doesn't exist then return -1, or allocate a new bin if allocate is set

Definition at line 790 of file THnSparse.cxx.

◆ GetChunk()

THnSparseArrayChunk* THnSparse::GetChunk ( Int_t idx ) const

inlineprotected

Definition at line 55 of file THnSparse.h.

◆ GetChunkSize()

Int_t THnSparse::GetChunkSize ( ) const

inline

Definition at line 86 of file THnSparse.h.

◆ GetCompactCoord()

THnSparseCompactBinCoord * THnSparse::GetCompactCoord ( ) const

protected

Return THnSparseCompactBinCoord object.

Definition at line 839 of file THnSparse.cxx.

◆ GetNbins()

Long64_t THnSparse::GetNbins ( ) const

inlinevirtual

Implements THnBase.

Definition at line 91 of file THnSparse.h.

◆ GetNChunks()

Int_t THnSparse::GetNChunks ( ) const

inline

Definition at line 87 of file THnSparse.h.

◆ GetSparseFractionBins()

Double_t THnSparse::GetSparseFractionBins ( ) const

Return the amount of filled bins over all bins.

Definition at line 855 of file THnSparse.cxx.

◆ GetSparseFractionMem()

Double_t THnSparse::GetSparseFractionMem ( ) const

Return the amount of used memory over memory that would be used by a non-sparse n-dimensional histogram.

The value is approximate.

Definition at line 866 of file THnSparse.cxx.

◆ InitStorage()

void THnSparse::InitStorage	(	Int_t *	nbins,
		Int_t	chunkSize
	)

protectedvirtual

Initialize the storage of a histogram created via Init()

Implements THnBase.

Definition at line 647 of file THnSparse.cxx.

◆ operator=()

THnSparse& THnSparse::operator= ( const THnSparse & )

private

◆ Projection() [1/4]

TH1D* THnSparse::Projection	(	Int_t	xDim,
		Option_t *	option = `""`
	)		const

inline

Definition at line 127 of file THnSparse.h.

◆ Projection() [2/4]

TH2D* THnSparse::Projection	(	Int_t	yDim,
		Int_t	xDim,
		Option_t *	option = `""`
	)		const

inline

Definition at line 134 of file THnSparse.h.

◆ Projection() [3/4]

TH3D* THnSparse::Projection	(	Int_t	xDim,
		Int_t	yDim,
		Int_t	zDim,
		Option_t *	option = `""`
	)		const

inline

Definition at line 142 of file THnSparse.h.

◆ Projection() [4/4]

THnSparse* THnSparse::Projection	(	Int_t	ndim,
		const Int_t *	dim,
		Option_t *	option = `""`
	)		const

inline

Definition at line 150 of file THnSparse.h.

◆ Rebin() [1/2]

THnSparse* THnSparse::Rebin ( Int_t group ) const

inline

Definition at line 155 of file THnSparse.h.

◆ Rebin() [2/2]

THnSparse* THnSparse::Rebin ( const Int_t * group ) const

inline

Definition at line 158 of file THnSparse.h.

◆ Reserve()

void THnSparse::Reserve ( Long64_t nbins )

protectedvirtual

Initialize storage for nbins.

Reimplemented from THnBase.

Definition at line 690 of file THnSparse.cxx.

◆ Reset()

void THnSparse::Reset ( Option_t * option = "" )

virtual

Clear the histogram.

Implements THnBase.

Definition at line 963 of file THnSparse.cxx.

◆ SetBinContent() [1/2]

void THnSparse::SetBinContent	(	const Int_t *	idx,
		Double_t	v
	)

inline

Definition at line 101 of file THnSparse.h.

◆ SetBinContent() [2/2]

void THnSparse::SetBinContent	(	Long64_t	bin,
		Double_t	v
	)

virtual

Set content of bin with index "bin" to "v".

Implements THnBase.

Definition at line 905 of file THnSparse.cxx.

◆ SetBinError2()

void THnSparse::SetBinError2	(	Long64_t	bin,
		Double_t	e2
	)

virtual

Set error of bin with index "bin" to "e", enable errors if needed.

Implements THnBase.

Definition at line 915 of file THnSparse.cxx.

◆ SetFilledBins()

void THnSparse::SetFilledBins ( Long64_t nbins )

inlinevirtual

Reimplemented from THnBase.

Definition at line 92 of file THnSparse.h.

◆ Sumw2()

void THnSparse::Sumw2 ( )

virtual

Enable calculation of errors.

Implements THnBase.

Definition at line 949 of file THnSparse.cxx.

Member Data Documentation

◆ fBinContent

TObjArray THnSparse::fBinContent

private

Definition at line 40 of file THnSparse.h.

◆ fBins

TExMap THnSparse::fBins

private

Definition at line 41 of file THnSparse.h.

◆ fBinsContinued

TExMap THnSparse::fBinsContinued

private

filled bins

Definition at line 42 of file THnSparse.h.

◆ fChunkSize

Int_t THnSparse::fChunkSize

private

Definition at line 38 of file THnSparse.h.

◆ fCompactCoord

THnSparseCompactBinCoord* THnSparse::fCompactCoord

private

filled bins for non-unique hashes, containing pairs of (bin index 0, bin index 1)

Definition at line 43 of file THnSparse.h.

◆ fFilledBins

Long64_t THnSparse::fFilledBins

private

Definition at line 39 of file THnSparse.h.

The documentation for this class was generated from the following files:

hist/hist/inc/THnSparse.h
hist/hist/src/THnSparse.cxx

Filling

Fast Bin Content Access

Efficiency

Projections

Internal Representation

Public Member Functions

Static Public Member Functions

Protected Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ THnSparse() [1/3]

◆ THnSparse() [2/3]

◆ THnSparse() [3/3]

◆ ~THnSparse()

Member Function Documentation

◆ AddBinContent() [1/2]

◆ AddBinContent() [2/2]

◆ AddBinError2()

◆ AddChunk()

◆ CreateIter()

◆ CreateSparse() [1/2]

◆ CreateSparse() [2/2]

◆ FillBin()

◆ FillExMap()

◆ GenerateArray()

◆ GetBin() [1/6]

◆ GetBin() [2/6]

◆ GetBin() [3/6]

◆ GetBin() [4/6]

◆ GetBin() [5/6]

◆ GetBin() [6/6]

◆ GetBinContent() [1/2]

◆ GetBinContent() [2/2]

◆ GetBinError2()

◆ GetBinIndexForCurrentBin()

◆ GetChunk()

◆ GetChunkSize()

◆ GetCompactCoord()

◆ GetNbins()

◆ GetNChunks()

◆ GetSparseFractionBins()

◆ GetSparseFractionMem()

◆ InitStorage()

◆ operator=()

◆ Projection() [1/4]

◆ Projection() [2/4]

◆ Projection() [3/4]

◆ Projection() [4/4]

◆ Rebin() [1/2]

◆ Rebin() [2/2]

◆ Reserve()

◆ Reset()

◆ SetBinContent() [1/2]

◆ SetBinContent() [2/2]

◆ SetBinError2()

◆ SetFilledBins()

◆ Sumw2()

Member Data Documentation

◆ fBinContent

◆ fBins

◆ fBinsContinued

◆ fChunkSize

◆ fCompactCoord

◆ fFilledBins