TGraphDelaunay2D generates a Delaunay triangulation of a TGraph2D.

The algorithm used for finding the triangles is based on CDT, a C++ library for generating constraint or conforming Delaunay triangulations.

The ROOT::Math::Delaunay2D class provides a wrapper for using the CDT library.

This implementation provides large improvements in terms of computational performances compared to the legacy one available in TGraphDelaunay, and it is by default used in TGraph2D. The old, legacy implementation can be still used when calling TGraph2D::GetHistogram and TGraph2D::Draw with the old option.

Definition of Delaunay triangulation (After B. Delaunay): For a set S of points in the Euclidean plane, the unique triangulation DT(S) of S such that no point in S is inside the circumcircle of any triangle in DT(S). DT(S) is the dual of the Voronoi diagram of S. If n is the number of points in S, the Voronoi diagram of S is the partitioning of the plane containing S points into n convex polygons such that each polygon contains exactly one point and every point in a given polygon is closer to its central point than to any other. A Voronoi diagram is sometimes also known as a Dirichlet tessellation.

This applet gives a nice practical view of Delaunay triangulation and Voronoi diagram.

Definition at line 32 of file TGraphDelaunay2D.h.

Public Types
typedef ROOT::Math::Delaunay2D::Triangles	Triangles

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

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

enum	EDeprecatedStatusBits { kObjInCanvas = (1ULL << ( 3 )) }

enum	EStatusBits { kCanDelete = (1ULL << ( 0 )) , kMustCleanup = (1ULL << ( 3 )) , kIsReferenced = (1ULL << ( 4 )) , kHasUUID = (1ULL << ( 5 )) , kCannotPick = (1ULL << ( 6 )) , kNoContextMenu = (1ULL << ( 8 )) , kInvalidObject = (1ULL << ( 13 )) }

Public Member Functions
	TGraphDelaunay2D (TGraph2D *g=nullptr)
	TGraphDelaunay2D normal constructor.

Triangles::const_iterator	begin () const

Double_t	ComputeZ (Double_t x, Double_t y)

Triangles::const_iterator	end () const

void	FindAllTriangles ()

TGraph2D *	GetGraph2D () const

Double_t	GetMarginBinsContent () const

Int_t	GetNdt () const

Double_t	GetXNmax () const

Double_t	GetXNmin () const

Double_t	GetYNmax () const

Double_t	GetYNmin () const

TClass *	IsA () const override

void	SetMarginBinsContent (Double_t z=0.)

void	Streamer (TBuffer &) override
	Stream an object of class TObject.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

Public Member Functions inherited from TNamed
	TNamed ()

	TNamed (const char name, const char title)

	TNamed (const TNamed &named)
	TNamed copy ctor.

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

virtual	~TNamed ()
	TNamed destructor.

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

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

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

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

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

const char *	GetName () const override
	Returns name of object.

const char *	GetTitle () const override
	Returns title of object.

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

TClass *	IsA () const override

Bool_t	IsSortable () const override

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

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

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

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

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

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

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

void	Streamer (TBuffer &) override
	Stream an object of class TObject.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

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

	TObject (const TObject &object)
	TObject copy ctor.

virtual	~TObject ()
	TObject destructor.

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

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

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

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.

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

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

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

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

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

virtual TObject *	DrawClone (Option_t *option="") const
	Draw a clone of this object in the current selected pad with: `gROOT->SetSelectedPad(c1)`.

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

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

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

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

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

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

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

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

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

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

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

virtual Option_t *	GetOption () const

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

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

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.

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

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

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

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

void	InvertBit (UInt_t f)

Bool_t	IsDestructed () const
	IsDestructed.

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

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

R__ALWAYS_INLINE Bool_t	IsOnHeap () const

R__ALWAYS_INLINE 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).

virtual Bool_t	Notify ()
	This method must be overridden to handle object notification (the base implementation is no-op).

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

void	operator delete (void *ptr)
	Operator delete.

void	operator delete (void ptr, void vp)
	Only called by placement new when throwing an exception.

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

void	operator delete[] (void ptr, void vp)
	Only called by placement new[] when throwing an exception.

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.

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

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

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

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

void	ResetBit (UInt_t f)

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

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

void	SetBit (UInt_t f)

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

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

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

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

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

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.

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

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

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

Static Public Member Functions
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

Static Public Member Functions inherited from TNamed
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

Static Public Member Functions inherited from TObject
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

static Longptr_t	GetDtorOnly ()
	Return destructor only flag.

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

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

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

Protected Attributes
ROOT::Math::Delaunay2D	fDelaunay
	! Delaunay interpolator class

TGraph2D *	fGraph2D
	! 2D graph containing the user data

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

Private Member Functions
	TGraphDelaunay2D (const TGraphDelaunay2D &)=delete

TGraphDelaunay2D &	operator= (const TGraphDelaunay2D &)=delete

Additional Inherited Members
Protected Types inherited from TObject
enum	{ kOnlyPrepStep = (1ULL << ( 3 )) }

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).

void	MakeZombie ()

#include <TGraphDelaunay2D.h>

Inheritance diagram for TGraphDelaunay2D:

[legend]

Member Typedef Documentation

◆ Triangles

typedef ROOT::Math::Delaunay2D::Triangles TGraphDelaunay2D::Triangles

Definition at line 48 of file TGraphDelaunay2D.h.

Constructor & Destructor Documentation

◆ TGraphDelaunay2D() [1/2]

TGraphDelaunay2D::TGraphDelaunay2D ( const TGraphDelaunay2D & )

privatedelete

◆ TGraphDelaunay2D() [2/2]

TGraphDelaunay2D::TGraphDelaunay2D ( TGraph2D * g = nullptr )

TGraphDelaunay2D normal constructor.

Definition at line 49 of file TGraphDelaunay2D.cxx.

Member Function Documentation

◆ begin()

Triangles::const_iterator TGraphDelaunay2D::begin ( ) const

inline

Definition at line 65 of file TGraphDelaunay2D.h.

◆ Class()

static TClass * TGraphDelaunay2D::Class ( )

static

Returns: TClass describing this class

◆ Class_Name()

static const char * TGraphDelaunay2D::Class_Name ( )

static

Returns: Name of this class

◆ Class_Version()

static constexpr Version_t TGraphDelaunay2D::Class_Version ( )

inlinestaticconstexpr

Returns: Version of this class

Definition at line 68 of file TGraphDelaunay2D.h.

◆ ComputeZ()

Double_t TGraphDelaunay2D::ComputeZ	(	Double_t	x,
		Double_t	y
	)

inline

Definition at line 52 of file TGraphDelaunay2D.h.

◆ DeclFileName()

static const char * TGraphDelaunay2D::DeclFileName ( )

inlinestatic

Returns: Name of the file containing the class declaration

Definition at line 68 of file TGraphDelaunay2D.h.

◆ end()

Triangles::const_iterator TGraphDelaunay2D::end ( ) const

inline

Definition at line 66 of file TGraphDelaunay2D.h.

◆ FindAllTriangles()

void TGraphDelaunay2D::FindAllTriangles ( )

inline

Definition at line 53 of file TGraphDelaunay2D.h.

◆ GetGraph2D()

TGraph2D * TGraphDelaunay2D::GetGraph2D ( ) const

inline

Definition at line 55 of file TGraphDelaunay2D.h.

◆ GetMarginBinsContent()

Double_t TGraphDelaunay2D::GetMarginBinsContent ( ) const

inline

Definition at line 56 of file TGraphDelaunay2D.h.

◆ GetNdt()

Int_t TGraphDelaunay2D::GetNdt ( ) const

inline

Definition at line 57 of file TGraphDelaunay2D.h.

◆ GetXNmax()

Double_t TGraphDelaunay2D::GetXNmax ( ) const

inline

Definition at line 59 of file TGraphDelaunay2D.h.

◆ GetXNmin()

Double_t TGraphDelaunay2D::GetXNmin ( ) const

inline

Definition at line 58 of file TGraphDelaunay2D.h.

◆ GetYNmax()

Double_t TGraphDelaunay2D::GetYNmax ( ) const

inline

Definition at line 61 of file TGraphDelaunay2D.h.

◆ GetYNmin()

Double_t TGraphDelaunay2D::GetYNmin ( ) const

inline

Definition at line 60 of file TGraphDelaunay2D.h.

◆ IsA()

TClass * TGraphDelaunay2D::IsA ( ) const

inlineoverridevirtual

Returns: TClass describing current object

Reimplemented from TObject.

Definition at line 68 of file TGraphDelaunay2D.h.

◆ operator=()

TGraphDelaunay2D & TGraphDelaunay2D::operator= ( const TGraphDelaunay2D & )

privatedelete

◆ SetMarginBinsContent()

void TGraphDelaunay2D::SetMarginBinsContent ( Double_t z = 0. )

inline

Definition at line 63 of file TGraphDelaunay2D.h.

◆ Streamer()

void TGraphDelaunay2D::Streamer ( TBuffer & R__b )

overridevirtual

Stream an object of class TObject.

Reimplemented from TObject.

◆ StreamerNVirtual()

void TGraphDelaunay2D::StreamerNVirtual ( TBuffer & ClassDef_StreamerNVirtual_b )

inline

Definition at line 68 of file TGraphDelaunay2D.h.

Member Data Documentation

◆ fDelaunay

ROOT::Math::Delaunay2D TGraphDelaunay2D::fDelaunay

protected

! Delaunay interpolator class

Definition at line 44 of file TGraphDelaunay2D.h.

◆ fGraph2D

TGraph2D* TGraphDelaunay2D::fGraph2D

protected

! 2D graph containing the user data

Definition at line 43 of file TGraphDelaunay2D.h.

Libraries for TGraphDelaunay2D:

[legend]

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

hist/hist/inc/TGraphDelaunay2D.h
hist/hist/src/TGraphDelaunay2D.cxx

Public Types

Public Member Functions

Static Public Member Functions

Protected Attributes

Private Member Functions

Additional Inherited Members

Member Typedef Documentation

◆ Triangles

Constructor & Destructor Documentation

◆ TGraphDelaunay2D() [1/2]

◆ TGraphDelaunay2D() [2/2]

Member Function Documentation

◆ begin()

◆ Class()

◆ Class_Name()

◆ Class_Version()

◆ ComputeZ()

◆ DeclFileName()

◆ end()

◆ FindAllTriangles()

◆ GetGraph2D()

◆ GetMarginBinsContent()

◆ GetNdt()

◆ GetXNmax()

◆ GetXNmin()

◆ GetYNmax()

◆ GetYNmin()

◆ IsA()

◆ operator=()

◆ SetMarginBinsContent()

◆ Streamer()

◆ StreamerNVirtual()

Member Data Documentation

◆ fDelaunay

◆ fGraph2D