Package org.jgrapht.alg.drawing

Class FRLayoutAlgorithm2D<V,E>

java.lang.Object

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 Object

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.

Author:

Dimitrios Michail

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
static int	DEFAULT_ITERATIONS	Default number of iterations
static double	DEFAULT_NORMALIZATION_FACTOR	Default normalization factor when calculating optimal distance
protected Function<V,Point2D>	initializer	A model initializer
protected int	iterations
protected double	normalizationFactor
protected double	optimalDistance
protected Random	rng
protected BiFunction<LayoutModel2D<V>,Integer,FRLayoutAlgorithm2D.TemperatureModel>	temperatureModelSupplier

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, Random rng)	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
Function<V,Point2D>	getInitializer()	Get the initializer
protected void	init(Graph<V,E> graph, LayoutModel2D<V> model)	Initialize a model using the initializer.
void	layout(Graph<V,E> graph, LayoutModel2D<V> model)	Layout a graph.
protected double	repulsiveForce(double distance)	Calculate the repulsive force.
void	setInitializer(Function<V,Point2D> initializer)	Set the initializer

Methods inherited from class java.lang.Object

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

Field Detail

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

initializer

protected Function<V,Point2D> initializer

A model initializer

Constructor Detail

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,
                           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 generators

Method Detail

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

getInitializer

public Function<V,Point2D> getInitializer()

Get the initializer

Returns:

the initializer

setInitializer

public void setInitializer(Function<V,Point2D> initializer)

Set the initializer

Parameters:

initializer - the initializer

init

protected void init(Graph<V,E> graph,
                    LayoutModel2D<V> model)

Initialize a model using the initializer.

Parameters:

graph - the graph

model - the model