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TGraphDelaunay2D Class Reference

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 ,
}

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 ()

TGraph2DGetGraph2D () 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

TClassIsA () 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 ("").

TObjectClone (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.

TClassIsA () const override

Bool_t IsSortable () const override

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

TNamedoperator= (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.

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 TObjectDrawClone (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 TObjectFindObject (const char *name) const
Must be redefined in derived classes.

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

virtual Option_tGetDrawOption () 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_tGetOption () 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)

TObjectoperator= (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 TClassClass ()

static const char * Class_Name ()

static constexpr Version_t Class_Version ()

static const char * DeclFileName ()

Static Public Member Functions inherited from TNamed
static TClassClass ()

static const char * Class_Name ()

static constexpr Version_t Class_Version ()

static const char * DeclFileName ()

Static Public Member Functions inherited from TObject
static TClassClass ()

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

TGraph2DfGraph2D
! 2D graph containing the user data

Protected Attributes inherited from TNamed
TString fName

TString fTitle

## Private Member Functions

TGraphDelaunay2D (const TGraphDelaunay2D &)=delete

TGraphDelaunay2Doperator= (const TGraphDelaunay2D &)=delete

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]

## ◆ Triangles

Definition at line 48 of file TGraphDelaunay2D.h.

## ◆ 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.

## ◆ 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.

## ◆ 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:

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