Class to generate a Delaunay triangulation of a 2D set of points.

Algorithm based on Triangle, a two-dimensional quality mesh generator and Delaunay triangulator from Jonathan Richard Shewchuk.

See [http://www.cs.cmu.edu/~quake/triangle.html]

Definition at line 73 of file Delaunay2D.h.

Classes
struct	Triangle

Public Types
typedef std::vector< Triangle >	Triangles

Public Member Functions
	Delaunay2D (int n, const double x, const double y, const double *z, double xmin=0, double xmax=0, double ymin=0, double ymax=0)
	class constructor from array of data points More...

void	SetInputPoints (int n, const double x, const double y, const double *z, double xmin=0, double xmax=0, double ymin=0, double ymax=0)
	set the input points for building the graph More...

double	Interpolate (double x, double y)
	Return the Interpolated z value corresponding to the (x,y) point. More...

void	FindAllTriangles ()
	Find all triangles. More...

Int_t	NumberOfTriangles () const
	return the number of triangles More...

double	XMin () const

double	XMax () const

double	YMin () const

double	YMax () const

void	SetZOuterValue (double z=0.)
	set z value to be returned for points outside the region More...

double	ZOuterValue () const
	return the user defined Z-outer value More...

Triangles::const_iterator	begin () const

Triangles::const_iterator	end () const

Protected Member Functions
unsigned int	Cell (UInt_t x, UInt_t y) const
	grid cells with containing triangles More...

int	CellX (double x) const

int	CellY (double y) const

Protected Attributes
Int_t	fNdt

Int_t	fNpoints
	Number of Delaunay triangles found. More...

const double *	fX
	Number of data points. More...

const double *	fY
	Pointer to X array (managed externally) More...

const double *	fZ
	Pointer to Y array. More...

double	fXNmin
	Pointer to Z array. More...

double	fXNmax
	Minimum value of fXN. More...

double	fYNmin
	Maximum value of fXN. More...

double	fYNmax
	Minimum value of fYN. More...

double	fOffsetX
	Maximum value of fYN. More...

double	fOffsetY
	Normalization offset X. More...

double	fScaleFactorX
	Normalization offset Y. More...

double	fScaleFactorY
	Normalization factor X. More...

double	fZout
	Normalization factor Y. More...

Bool_t	fInit
	Height for points lying outside the convex hull. More...

Triangles	fTriangles
	True if FindAllTriangels() has been performed. More...

std::vector< double >	fXN
	Triangles of Triangulation. More...

std::vector< double >	fYN
	normalized X More...

double	fXCellStep
	number of cells to divide the normalized space More...

double	fYCellStep
	inverse denominator to calculate X cell = fNCells / (fXNmax - fXNmin) More...

std::set< UInt_t >	fCells [(fNCells+1)*(fNCells+1)]
	inverse denominator to calculate X cell = fNCells / (fYNmax - fYNmin) More...

Static Protected Attributes
static const int	fNCells = 25
	normalized Y More...

Private Member Functions
double	Linear_transform (double x, double offset, double factor)

void	DoNormalizePoints ()
	internal function to normalize the points More...

void	DoFindTriangles ()
	internal function to find the triangle use Triangle or CGAL if flag is set More...

double	DoInterpolateNormalized (double x, double y)
	internal method to compute the interpolation More...

	Delaunay2D (const Delaunay2D &)

Delaunay2D &	operator= (const Delaunay2D &)

#include <Math/Delaunay2D.h>

Collaboration diagram for ROOT::Math::Delaunay2D:

Member Typedef Documentation

typedef std::vector<Triangle> ROOT::Math::Delaunay2D::Triangles

Definition at line 87 of file Delaunay2D.h.

Constructor & Destructor Documentation

ROOT::Math::Delaunay2D::Delaunay2D	(	int	n,
		const double *	x,
		const double *	y,
		const double *	z,
		double	xmin = `0`,
		double	xmax = `0`,
		double	ymin = `0`,
		double	ymax = `0`
	)

class constructor from array of data points

Definition at line 32 of file Delaunay2D.cxx.

ROOT::Math::Delaunay2D::Delaunay2D ( const Delaunay2D & )

private

Member Function Documentation

Triangles::const_iterator ROOT::Math::Delaunay2D::begin ( ) const

inline

Definition at line 118 of file Delaunay2D.h.

Referenced by TGraphDelaunay2D::begin().

unsigned int ROOT::Math::Delaunay2D::Cell	(	UInt_t	x,
		UInt_t	y
	)		const

inlineprotected

grid cells with containing triangles

Definition at line 276 of file Delaunay2D.h.

Referenced by DoFindTriangles(), and DoInterpolateNormalized().

int ROOT::Math::Delaunay2D::CellX ( double x ) const

inlineprotected

Definition at line 280 of file Delaunay2D.h.

Referenced by DoFindTriangles(), and DoInterpolateNormalized().

int ROOT::Math::Delaunay2D::CellY ( double y ) const

inlineprotected

Definition at line 284 of file Delaunay2D.h.

Referenced by DoFindTriangles(), and DoInterpolateNormalized().

void ROOT::Math::Delaunay2D::DoFindTriangles ( )

private

internal function to find the triangle use Triangle or CGAL if flag is set

Triangle implementation for finding all the triangles.

Definition at line 253 of file Delaunay2D.cxx.

Referenced by FindAllTriangles().

double ROOT::Math::Delaunay2D::DoInterpolateNormalized	(	double	xx,
		double	yy
	)

private

internal method to compute the interpolation

Triangle implementation for interpolation Finds the Delaunay triangle that the point (xi,yi) sits in (if any) and calculate a z-value for it by linearly interpolating the z-values that make up that triangle.

Definition at line 376 of file Delaunay2D.cxx.

Referenced by Interpolate().

void ROOT::Math::Delaunay2D::DoNormalizePoints ( )

private

internal function to normalize the points

Triangle implementation for normalizing the points.

Definition at line 241 of file Delaunay2D.cxx.

Referenced by FindAllTriangles().

Triangles::const_iterator ROOT::Math::Delaunay2D::end ( ) const

inline

Definition at line 119 of file Delaunay2D.h.

Referenced by TGraphDelaunay2D::end().

void ROOT::Math::Delaunay2D::FindAllTriangles ( )

Find all triangles.

Definition at line 125 of file Delaunay2D.cxx.

Referenced by TGraphDelaunay2D::FindAllTriangles(), and Interpolate().

double ROOT::Math::Delaunay2D::Interpolate	(	double	x,
		double	y
	)

Return the Interpolated z value corresponding to the (x,y) point.

Definition at line 101 of file Delaunay2D.cxx.

Referenced by TGraphDelaunay2D::ComputeZ().

double ROOT::Math::Delaunay2D::Linear_transform	(	double	x,
		double	offset,
		double	factor
	)

inlineprivate

Definition at line 127 of file Delaunay2D.h.

Referenced by DoNormalizePoints(), Interpolate(), and SetInputPoints().

Int_t ROOT::Math::Delaunay2D::NumberOfTriangles ( ) const

inline

return the number of triangles

Definition at line 104 of file Delaunay2D.h.

Referenced by TGraphDelaunay2D::GetNdt().

Delaunay2D& ROOT::Math::Delaunay2D::operator= ( const Delaunay2D & )

private

void ROOT::Math::Delaunay2D::SetInputPoints	(	int	n,
		const double *	x,
		const double *	y,
		const double *	z,
		double	xmin = `0`,
		double	xmax = `0`,
		double	ymin = `0`,
		double	ymax = `0`
	)