The Pivot MDS (multi-dimensional scaling) layout algorithm. More...

#include <ogdf/energybased/PivotMDS.h>

Inheritance diagram for ogdf::PivotMDS:

Public Member Functions
	PivotMDS ()

virtual	~PivotMDS ()

virtual void	call (GraphAttributes &GA) override
	Calls the layout algorithm for graph attributes `GA`.

bool	isForcing2DLayout () const
	Returns whether a 2D-layout is calculated even when GraphAttributes::threeD is set.

void	setEdgeCosts (double edgeCosts)
	Sets the desired distance between adjacent nodes. If the new value is smaller or equal 0 the default value (100) is used.

void	setForcing2DLayout (bool forcing2DLayout)
	Sets whether a 2D-layout should be calculated even when GraphAttributes::threeD is set.

void	setNumberOfPivots (int numberOfPivots)
	Sets the number of pivots. If the new value is smaller or equal 0 the default value (250) is used.

bool	useEdgeCostsAttribute () const

void	useEdgeCostsAttribute (bool useEdgeCostsAttribute)

Public Member Functions inherited from ogdf::LayoutModule
	LayoutModule ()
	Initializes a layout module.

virtual	~LayoutModule ()

void	operator() (GraphAttributes &GA)
	Computes a layout of graph `GA`.

Private Member Functions
void	centerPivotmatrix (Array< Array< double > > &pivotMatrix)
	Centers the pivot matrix.

void	copySPSS (Array< double > &copyTo, NodeArray< double > &copyFrom)

void	doPathLayout (GraphAttributes &GA, const node &v)
	Computes the layout of a path.

void	eigenValueDecomposition (Array< Array< double > > &K, Array< Array< double > > &eVecs, Array< double > &eValues)
	Computes the eigen value decomposition based on power iteration.

void	getPivotDistanceMatrix (const GraphAttributes &GA, Array< Array< double > > &pivDistMatrix)
	Computes the pivot distance matrix based on the maxmin strategy.

node	getRootedPath (const Graph &G)
	Checks whether the given graph is a path or not.

double	normalize (Array< double > &x)
	Normalizes the vector `x`.

void	pivotMDSLayout (GraphAttributes &GA)
	Computes the pivot mds layout of the given connected graph of `GA`.

double	prod (const Array< double > &x, const Array< double > &y)
	Computes the product of two vectors `x` and `y`.

void	randomize (Array< Array< double > > &matrix)
	Fills the given `matrix` with random doubles d 0 <= d <= 1.

void	selfProduct (const Array< Array< double > > &d, Array< Array< double > > &result)
	Computes the self product of `d`.

void	singularValueDecomposition (Array< Array< double > > &K, Array< Array< double > > &eVecs, Array< double > &eVals)
	Computes the singular value decomposition of matrix `K`.

Private Attributes
int	m_dimensionCount
	The dimension count determines the number of evecs that will be computed. Nevertheless PivotMDS only takes the first two with the highest eigenwert into account.

double	m_edgeCosts
	The costs to traverse an edge.

bool	m_forcing2DLayout
	Whether a 2D-layout is calculated even when GraphAttributes::threeD is set.

bool	m_hasEdgeCostsAttribute
	Tells whether the pivot mds is based on uniform edge costs or a edge costs attribute.

int	m_numberOfPivots
	The number of pivots.

Static Private Attributes
static const double	EPSILON
	Convergence factor used for power iteration.

static const double	FACTOR
	Factor used to center the pivot matrix.

static const unsigned int	SEED = 0
	Seed of the random number generator.

Detailed Description

The Pivot MDS (multi-dimensional scaling) layout algorithm.

Definition at line 52 of file PivotMDS.h.

Constructor & Destructor Documentation

◆ PivotMDS()

ogdf::PivotMDS::PivotMDS ( )

inline

Definition at line 54 of file PivotMDS.h.

◆ ~PivotMDS()

virtual ogdf::PivotMDS::~PivotMDS ( )

inlinevirtual

Definition at line 61 of file PivotMDS.h.

Member Function Documentation

◆ call()

virtual void ogdf::PivotMDS::call ( GraphAttributes & GA )

overridevirtual

Calls the layout algorithm for graph attributes GA.

Calculates a 3D-layout if GraphAttributes::threeD is set for GA, and a 2D-layout otherwise. You can use setForcing2DLayout() to force the calculation of a 2D-layout even when GraphAttributes::threeD is set.

Implements ogdf::LayoutModule.

◆ centerPivotmatrix()

void ogdf::PivotMDS::centerPivotmatrix ( Array< Array< double > > & pivotMatrix )

private

Centers the pivot matrix.

◆ copySPSS()

void ogdf::PivotMDS::copySPSS	(	Array< double > &	copyTo,
		NodeArray< double > &	copyFrom
	)

private

◆ doPathLayout()

void ogdf::PivotMDS::doPathLayout	(	GraphAttributes &	GA,
		const node &	v
	)

private

Computes the layout of a path.

◆ eigenValueDecomposition()

void ogdf::PivotMDS::eigenValueDecomposition	(	Array< Array< double > > &	K,
		Array< Array< double > > &	eVecs,
		Array< double > &	eValues
	)

private

Computes the eigen value decomposition based on power iteration.

◆ getPivotDistanceMatrix()

void ogdf::PivotMDS::getPivotDistanceMatrix	(	const GraphAttributes &	GA,
		Array< Array< double > > &	pivDistMatrix
	)

private

Computes the pivot distance matrix based on the maxmin strategy.

◆ getRootedPath()

node ogdf::PivotMDS::getRootedPath ( const Graph & G )

private

Checks whether the given graph is a path or not.

◆ isForcing2DLayout()

bool ogdf::PivotMDS::isForcing2DLayout ( ) const

inline

Returns whether a 2D-layout is calculated even when GraphAttributes::threeD is set.

Definition at line 79 of file PivotMDS.h.

◆ normalize()

double ogdf::PivotMDS::normalize ( Array< double > & x )

private

Normalizes the vector x.

◆ pivotMDSLayout()

void ogdf::PivotMDS::pivotMDSLayout ( GraphAttributes & GA )

private

Computes the pivot mds layout of the given connected graph of GA.

◆ prod()

double ogdf::PivotMDS::prod	(	const Array< double > &	x,
		const Array< double > &	y
	)

private

Computes the product of two vectors x and y.

◆ randomize()

void ogdf::PivotMDS::randomize ( Array< Array< double > > & matrix )

private

Fills the given matrix with random doubles d 0 <= d <= 1.

◆ selfProduct()

void ogdf::PivotMDS::selfProduct	(	const Array< Array< double > > &	d,
		Array< Array< double > > &	result
	)

private

Computes the self product of d.

◆ setEdgeCosts()

void ogdf::PivotMDS::setEdgeCosts ( double edgeCosts )

inline

Sets the desired distance between adjacent nodes. If the new value is smaller or equal 0 the default value (100) is used.

Definition at line 71 of file PivotMDS.h.

◆ setForcing2DLayout()

void ogdf::PivotMDS::setForcing2DLayout ( bool forcing2DLayout )

inline

Sets whether a 2D-layout should be calculated even when GraphAttributes::threeD is set.

Definition at line 75 of file PivotMDS.h.

◆ setNumberOfPivots()

void ogdf::PivotMDS::setNumberOfPivots ( int numberOfPivots )

inline

Sets the number of pivots. If the new value is smaller or equal 0 the default value (250) is used.

Definition at line 65 of file PivotMDS.h.

◆ singularValueDecomposition()

void ogdf::PivotMDS::singularValueDecomposition	(	Array< Array< double > > &	K,
		Array< Array< double > > &	eVecs,
		Array< double > &	eVals
	)

private

Computes the singular value decomposition of matrix K.

◆ useEdgeCostsAttribute() [1/2]

bool ogdf::PivotMDS::useEdgeCostsAttribute ( ) const

inline

Definition at line 94 of file PivotMDS.h.

◆ useEdgeCostsAttribute() [2/2]

void ogdf::PivotMDS::useEdgeCostsAttribute ( bool useEdgeCostsAttribute )

inline

Definition at line 90 of file PivotMDS.h.

Member Data Documentation

◆ EPSILON

const double ogdf::PivotMDS::EPSILON

staticprivate

Convergence factor used for power iteration.

Definition at line 98 of file PivotMDS.h.

◆ FACTOR

const double ogdf::PivotMDS::FACTOR

staticprivate

Factor used to center the pivot matrix.

Definition at line 101 of file PivotMDS.h.

◆ m_dimensionCount

int ogdf::PivotMDS::m_dimensionCount

private

The dimension count determines the number of evecs that will be computed. Nevertheless PivotMDS only takes the first two with the highest eigenwert into account.

Definition at line 112 of file PivotMDS.h.

◆ m_edgeCosts

double ogdf::PivotMDS::m_edgeCosts

private

The costs to traverse an edge.

Definition at line 115 of file PivotMDS.h.

◆ m_forcing2DLayout

bool ogdf::PivotMDS::m_forcing2DLayout

private

Whether a 2D-layout is calculated even when GraphAttributes::threeD is set.

Definition at line 123 of file PivotMDS.h.

◆ m_hasEdgeCostsAttribute

bool ogdf::PivotMDS::m_hasEdgeCostsAttribute

private

Tells whether the pivot mds is based on uniform edge costs or a edge costs attribute.

Definition at line 119 of file PivotMDS.h.

◆ m_numberOfPivots

int ogdf::PivotMDS::m_numberOfPivots

private

The number of pivots.

Definition at line 107 of file PivotMDS.h.

◆ SEED

const unsigned int ogdf::PivotMDS::SEED = 0

staticprivate

Seed of the random number generator.

Definition at line 104 of file PivotMDS.h.

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

include/ogdf/energybased/PivotMDS.h

OpenGraph DrawingFramework

Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ PivotMDS()

◆ ~PivotMDS()

Member Function Documentation

◆ call()

◆ centerPivotmatrix()

◆ copySPSS()

◆ doPathLayout()

◆ eigenValueDecomposition()

◆ getPivotDistanceMatrix()

◆ getRootedPath()

◆ isForcing2DLayout()

◆ normalize()

◆ pivotMDSLayout()

◆ prod()

◆ randomize()

◆ selfProduct()

◆ setEdgeCosts()

◆ setForcing2DLayout()

◆ setNumberOfPivots()

◆ singularValueDecomposition()

◆ useEdgeCostsAttribute() [1/2]

◆ useEdgeCostsAttribute() [2/2]

Member Data Documentation

◆ EPSILON

◆ FACTOR

◆ m_dimensionCount

◆ m_edgeCosts

◆ m_forcing2DLayout

◆ m_hasEdgeCostsAttribute

◆ m_numberOfPivots

◆ SEED

Open
Graph Drawing
Framework