nl.cwts.networkanalysis

Class VOSLayoutAlgorithm

java.lang.Object

nl.cwts.networkanalysis.VOSLayoutAlgorithm

All Implemented Interfaces:

java.lang.Cloneable, LayoutAlgorithm, QualityLayoutAlgorithm

Direct Known Subclasses:

GradientDescentVOSLayoutAlgorithm

public abstract class VOSLayoutAlgorithm
extends java.lang.Object
implements java.lang.Cloneable, QualityLayoutAlgorithm

Abstract base class for layout algorithms that use the VOS quality function.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	attraction Attraction parameter.
static int	DEFAULT_ATTRACTION Default attraction parameter.
static double	DEFAULT_EDGE_WEIGHT_INCREMENT Default edge weight increment parameter.
static int	DEFAULT_REPULSION Default repulsion parameter.
protected double	edgeWeightIncrement Edge weight increment parameter.
protected int	repulsion Repulsion parameter.

Constructor Summary

Constructors

Constructor and Description
VOSLayoutAlgorithm() Constructs a VOS layout algorithm.
VOSLayoutAlgorithm(int attraction, int repulsion, double edgeWeightIncrement) Constructs a VOS layout algorithm with a specified attraction parameter, repulsion parameter, and edge weight increment parameter.

Method Summary

Modifier and Type	Method and Description
double	calcQuality(Network network, Layout layout) Calculates the quality of a layout using the VOS quality function.
VOSLayoutAlgorithm	clone() Clones the algorithm.
int	getAttraction() Returns the attraction parameter.
double	getEdgeWeightIncrement() Returns the edge weight increment parameter.
int	getRepulsion() Returns the repulsion parameter.
void	setAttraction(int attraction) Sets the attraction parameter.
void	setEdgeWeightIncrement(double edgeWeightIncrement) Sets the edge weight increment parameter.
void	setRepulsion(int repulsion) Sets the repulsion parameter.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface nl.cwts.networkanalysis.LayoutAlgorithm

findLayout

Field Detail

DEFAULT_ATTRACTION

public static final int DEFAULT_ATTRACTION

Default attraction parameter.

See Also:

Constant Field Values

DEFAULT_REPULSION

public static final int DEFAULT_REPULSION

Default repulsion parameter.

See Also:

Constant Field Values

DEFAULT_EDGE_WEIGHT_INCREMENT

public static final double DEFAULT_EDGE_WEIGHT_INCREMENT

Default edge weight increment parameter.

See Also:

Constant Field Values

attraction

protected int attraction

Attraction parameter.

repulsion

protected int repulsion

Repulsion parameter.

edgeWeightIncrement

protected double edgeWeightIncrement

Edge weight increment parameter.

Constructor Detail

VOSLayoutAlgorithm

public VOSLayoutAlgorithm()

Constructs a VOS layout algorithm.

VOSLayoutAlgorithm

public VOSLayoutAlgorithm(int attraction,
                          int repulsion,
                          double edgeWeightIncrement)

Constructs a VOS layout algorithm with a specified attraction parameter, repulsion parameter, and edge weight increment parameter.

Parameters:

attraction - Attraction parameter

repulsion - Repulsion parameter

edgeWeightIncrement - Edge weight increment parameter

Method Detail

clone

public VOSLayoutAlgorithm clone()

Clones the algorithm.

Overrides:

clone in class java.lang.Object

Returns:

Cloned algorithm

getAttraction

public int getAttraction()

Returns the attraction parameter.

Returns:

Attraction parameter

getRepulsion

public int getRepulsion()

Returns the repulsion parameter.

Returns:

Repulsion parameter

getEdgeWeightIncrement

public double getEdgeWeightIncrement()

Returns the edge weight increment parameter.

Returns:

Edge weight increment parameter

setAttraction

public void setAttraction(int attraction)

Sets the attraction parameter.

Parameters:

attraction - Attraction parameter

setRepulsion

public void setRepulsion(int repulsion)

Sets the repulsion parameter.

Parameters:

repulsion - Repulsion parameter

setEdgeWeightIncrement

public void setEdgeWeightIncrement(double edgeWeightIncrement)

Sets the edge weight increment parameter.

Parameters:

edgeWeightIncrement - Edge weight increment parameter

calcQuality

public double calcQuality(Network network,
                          Layout layout)

Calculates the quality of a layout using the VOS quality function.

The VOS quality function is given by

1 / attraction * sum(a[i][j] * d(x[i], x[j]) ^ attraction) - 1 / repulsion * sum(d(x[i], x[j]) ^ repulsion),

where a[i][j] is the weight of the edge between nodes i and j and x[i] = (x[i][1], x[i][2]) are the coordinates of node i. The function d(x[i], x[j]) is the Euclidean distance between nodes i and j. The sum is taken over all pairs of nodes i and j with j < i. The attraction parameter must be greater than the repulsion parameter. The lower the value of the VOS quality function, the higher the quality of the layout.

Specified by:

calcQuality in interface QualityLayoutAlgorithm

Parameters:

network - Network

layout - Layout

Returns:

Quality of the layout