Class FRLayoutAlgorithm2D<V,E>

java.lang.Object

org.jgrapht.alg.drawing.BaseLayoutAlgorithm2D<V,E>

org.jgrapht.alg.drawing.FRLayoutAlgorithm2D<V,E>

Type Parameters:

V - the vertex type

E - the edge type

All Implemented Interfaces:

LayoutAlgorithm2D<V,E>

Direct Known Subclasses:

IndexedFRLayoutAlgorithm2D

public class FRLayoutAlgorithm2D<V,E>
extends BaseLayoutAlgorithm2D<V,E>

Fruchterman and Reingold Force-Directed Placement Algorithm. The algorithm belongs in the broad category of force directed graph drawing algorithms and is described in the paper:

• Thomas M. J. Fruchterman and Edward M. Reingold. Graph drawing by force-directed placement. Software: Practice and experience, 21(11):1129--1164, 1991.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	FRLayoutAlgorithm2D.InverseLinearTemperatureModel	An inverse linear temperature model.
static interface	FRLayoutAlgorithm2D.TemperatureModel	A general interface for a temperature model.

Field Summary

Fields

Modifier and Type	Field	Description
protected final ToleranceDoubleComparator	comparator
static final int	DEFAULT_ITERATIONS	Default number of iterations
static final double	DEFAULT_NORMALIZATION_FACTOR	Default normalization factor when calculating optimal distance
protected int	iterations
protected double	normalizationFactor
protected double	optimalDistance
protected Random	rng
protected BiFunction<LayoutModel2D<V>, Integer, FRLayoutAlgorithm2D.TemperatureModel>	temperatureModelSupplier

Fields inherited from class BaseLayoutAlgorithm2D

initializer

Constructor Summary

Constructors

Constructor	Description
FRLayoutAlgorithm2D()	Create a new layout algorithm
FRLayoutAlgorithm2D(int iterations)	Create a new layout algorithm
FRLayoutAlgorithm2D(int iterations, double normalizationFactor)	Create a new layout algorithm
FRLayoutAlgorithm2D(int iterations, double normalizationFactor, BiFunction<LayoutModel2D<V>, Integer, FRLayoutAlgorithm2D.TemperatureModel> temperatureModelSupplier, Random rng)	Create a new layout algorithm
FRLayoutAlgorithm2D(int iterations, double normalizationFactor, BiFunction<LayoutModel2D<V>, Integer, FRLayoutAlgorithm2D.TemperatureModel> temperatureModelSupplier, Random rng, double tolerance)	Create a new layout algorithm
FRLayoutAlgorithm2D(int iterations, double normalizationFactor, Random rng)	Create a new layout algorithm
FRLayoutAlgorithm2D(int iterations, double normalizationFactor, Random rng, double tolerance)	Create a new layout algorithm

Method Summary

Modifier and Type	Method	Description
protected double	attractiveForce(double distance)	Calculate the attractive force.
protected Map<V,Point2D>	calculateAttractiveForces(Graph<V,E> graph, LayoutModel2D<V> model)	Calculate the repulsive forces between vertices connected with edges.
protected Map<V,Point2D>	calculateRepulsiveForces(Graph<V,E> graph, LayoutModel2D<V> model)	Calculate the repulsive forces between vertices
void	layout(Graph<V,E> graph, LayoutModel2D<V> model)	Layout a graph.
protected double	repulsiveForce(double distance)	Calculate the repulsive force.

Methods inherited from class BaseLayoutAlgorithm2D

getInitializer, init, setInitializer

Methods inherited from class Object

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

Field Details

DEFAULT_ITERATIONS

public static final int DEFAULT_ITERATIONS

Default number of iterations

See Also:

• Constant Field Values

DEFAULT_NORMALIZATION_FACTOR

public static final double DEFAULT_NORMALIZATION_FACTOR

Default normalization factor when calculating optimal distance

See Also:

• Constant Field Values

rng

protected Random rng

optimalDistance

protected double optimalDistance

normalizationFactor

protected double normalizationFactor

iterations

protected int iterations

temperatureModelSupplier

protected BiFunction<LayoutModel2D<V>, Integer, FRLayoutAlgorithm2D.TemperatureModel> temperatureModelSupplier

comparator

protected final ToleranceDoubleComparator comparator

Constructor Details

FRLayoutAlgorithm2D

public FRLayoutAlgorithm2D()

Create a new layout algorithm

FRLayoutAlgorithm2D

public FRLayoutAlgorithm2D(int iterations)

Create a new layout algorithm

Parameters:

iterations - number of iterations

FRLayoutAlgorithm2D

public FRLayoutAlgorithm2D(int iterations,
 double normalizationFactor)

Create a new layout algorithm

Parameters:

iterations - number of iterations

normalizationFactor - normalization factor for the optimal distance

FRLayoutAlgorithm2D

public FRLayoutAlgorithm2D(int iterations,
 double normalizationFactor,
 Random rng)

Create a new layout algorithm

Parameters:

iterations - number of iterations

normalizationFactor - normalization factor for the optimal distance

rng - the random number generator

FRLayoutAlgorithm2D

public FRLayoutAlgorithm2D(int iterations,
 double normalizationFactor,
 Random rng,
 double tolerance)

Create a new layout algorithm

Parameters:

iterations - number of iterations

normalizationFactor - normalization factor for the optimal distance

rng - the random number generator

tolerance - tolerance used when comparing floating point values

FRLayoutAlgorithm2D

public FRLayoutAlgorithm2D(int iterations,
 double normalizationFactor,
 BiFunction<LayoutModel2D<V>, Integer, FRLayoutAlgorithm2D.TemperatureModel> temperatureModelSupplier,
 Random rng)

Create a new layout algorithm

Parameters:

iterations - number of iterations

normalizationFactor - normalization factor for the optimal distance

temperatureModelSupplier - a simulated annealing temperature model supplier

rng - the random number generator

FRLayoutAlgorithm2D

public FRLayoutAlgorithm2D(int iterations,
 double normalizationFactor,
 BiFunction<LayoutModel2D<V>, Integer, FRLayoutAlgorithm2D.TemperatureModel> temperatureModelSupplier,
 Random rng,
 double tolerance)

Create a new layout algorithm

Parameters:

iterations - number of iterations

normalizationFactor - normalization factor for the optimal distance

temperatureModelSupplier - a simulated annealing temperature model supplier

rng - the random number generator

tolerance - tolerance used when comparing floating point values

Method Details

layout

public void layout(Graph<V,E> graph,
 LayoutModel2D<V> model)

Description copied from interface: LayoutAlgorithm2D

Layout a graph.

Parameters:

graph - the graph

model - the layout model to use

attractiveForce

protected double attractiveForce(double distance)

Calculate the attractive force.

Parameters:

distance - the distance

Returns:

the force

repulsiveForce

protected double repulsiveForce(double distance)

Calculate the repulsive force.

Parameters:

distance - the distance

Returns:

the force

calculateRepulsiveForces

protected Map<V,Point2D> calculateRepulsiveForces(Graph<V,E> graph,
 LayoutModel2D<V> model)

Calculate the repulsive forces between vertices

Parameters:

graph - the graph

model - the model

Returns:

the displacement per vertex due to the repulsive forces

calculateAttractiveForces

protected Map<V,Point2D> calculateAttractiveForces(Graph<V,E> graph,
 LayoutModel2D<V> model)

Calculate the repulsive forces between vertices connected with edges.

Parameters:

graph - the graph

model - the model

Returns:

the displacement per vertex due to the attractive forces