edu.uci.ics.jung.algorithms.layout
Class FRLayout2<V,E>

java.lang.Object
  edu.uci.ics.jung.algorithms.layout.AbstractLayout<V,E>
      edu.uci.ics.jung.algorithms.layout.FRLayout2<V,E>

All Implemented Interfaces:

Layout<V,E>, IterativeContext, org.apache.commons.collections15.Transformer<V,Point2D>

public class FRLayout2<V,E>
extends AbstractLayout<V,E>
implements IterativeContext

Implements the Fruchterman-Reingold force-directed algorithm for node layout. This is an experimental attempt at optimizing FRLayout; if it is successful it will be folded back into FRLayout (and this class will disappear).

Behavior is determined by the following settable parameters:

• attraction multiplier: how much edges try to keep their vertices together
• repulsion multiplier: how much vertices try to push each other apart
• maximum iterations: how many iterations this algorithm will use before stopping

Each of the first two defaults to 0.75; the maximum number of iterations defaults to 700.

Author:

Tom Nelson, Scott White, Yan-Biao Boey, Danyel Fisher

See Also:

"Fruchterman and Reingold, 'Graph Drawing by Force-directed Placement'", http://i11www.ilkd.uni-karlsruhe.de/teaching/SS_04/visualisierung/papers/fruchterman91graph.pdf

Field Summary

Fields inherited from class edu.uci.ics.jung.algorithms.layout.AbstractLayout

graph, initialized, locations, size

Constructor Summary

FRLayout2(Graph<V,E> g)
Creates an instance for the specified graph.

FRLayout2(Graph<V,E> g, Dimension d)
Creates an instance of size d for the specified graph.

Method Summary

protected void	calcAttraction(E e)
protected void	calcPositions(V v)
protected void	calcRepulsion(V v1)
boolean	done() Returns true once the current iteration has passed the maximum count, MAX_ITERATIONS.
void	initialize() Initializes fields in the node that may not have been set during the constructor.
boolean	isIncremental() This one is an incremental visualization.
void	reset()
void	setAttractionMultiplier(double attraction) Sets the attraction multiplier.
void	setMaxIterations(int maxIterations) Sets the maximum number of iterations.
void	setRepulsionMultiplier(double repulsion) Sets the repulsion multiplier.
void	setSize(Dimension size) When a visualization is resized, it presumably wants to fix the locations of the vertices and possibly to reinitialize its data.
void	step() Moves the iteration forward one notch, calculation attraction and repulsion between vertices and edges and cooling the temperature.

Methods inherited from class edu.uci.ics.jung.algorithms.layout.AbstractLayout

getGraph, getSize, getX, getY, isLocked, lock, lock, offsetVertex, setGraph, setInitializer, setLocation, setLocation, transform

Methods inherited from class java.lang.Object

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

Constructor Detail

FRLayout2

public FRLayout2(Graph<V,E> g)

Creates an instance for the specified graph.

FRLayout2

public FRLayout2(Graph<V,E> g,
                 Dimension d)

Creates an instance of size d for the specified graph.

Method Detail

setSize

public void setSize(Dimension size)

Description copied from class: AbstractLayout

When a visualization is resized, it presumably wants to fix the locations of the vertices and possibly to reinitialize its data. The current method calls initializeLocations followed by initialize_local.

Specified by:

setSize in interface Layout<V,E>

Overrides:

setSize in class AbstractLayout<V,E>

setAttractionMultiplier

public void setAttractionMultiplier(double attraction)

Sets the attraction multiplier.

setRepulsionMultiplier

public void setRepulsionMultiplier(double repulsion)

Sets the repulsion multiplier.

reset

public void reset()

Specified by:

reset in interface Layout<V,E>

initialize

public void initialize()

Description copied from interface: Layout

Initializes fields in the node that may not have been set during the constructor. Must be called before the iterations begin.

Specified by:

initialize in interface Layout<V,E>

step

public void step()

Moves the iteration forward one notch, calculation attraction and repulsion between vertices and edges and cooling the temperature.

Specified by:

step in interface IterativeContext

calcPositions

protected void calcPositions(V v)

calcAttraction

protected void calcAttraction(E e)

calcRepulsion

protected void calcRepulsion(V v1)

setMaxIterations

public void setMaxIterations(int maxIterations)

Sets the maximum number of iterations.

isIncremental

public boolean isIncremental()

This one is an incremental visualization.

done

public boolean done()

Returns true once the current iteration has passed the maximum count, MAX_ITERATIONS.

Specified by:

done in interface IterativeContext