Class IndexedFRLayoutAlgorithm2D<V,E>

java.lang.Object

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

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

org.jgrapht.alg.drawing.IndexedFRLayoutAlgorithm2D<V,E>

Type Parameters:

V - the graph vertex type

E - the graph edge type

All Implemented Interfaces:

LayoutAlgorithm2D<V,E>

public class IndexedFRLayoutAlgorithm2D<V,E>
extends FRLayoutAlgorithm2D<V,E>

Fruchterman and Reingold Force-Directed Placement Algorithm using the Barnes-Hut indexing technique with a QuadTree. The Barnes-Hut indexing technique is described in the following paper:

• J. Barnes and P. Hut. A hierarchical O(N log N) force-calculation algorithm. Nature. 324(4):446--449, 1986.

Nested Class Summary

Nested classes/interfaces inherited from class FRLayoutAlgorithm2D

FRLayoutAlgorithm2D.InverseLinearTemperatureModel, FRLayoutAlgorithm2D.TemperatureModel

Field Summary

Fields

Modifier and Type	Field	Description
static final double	DEFAULT_THETA_FACTOR	Default $\theta$ value for approximation using the Barnes-Hut technique
protected long	savedComparisons
protected double	theta

Fields inherited from class FRLayoutAlgorithm2D

comparator, DEFAULT_ITERATIONS, DEFAULT_NORMALIZATION_FACTOR, iterations, normalizationFactor, optimalDistance, rng, temperatureModelSupplier

Fields inherited from class BaseLayoutAlgorithm2D

initializer

Constructor Summary

Constructors

Constructor	Description
IndexedFRLayoutAlgorithm2D()	Create a new layout algorithm
IndexedFRLayoutAlgorithm2D(int iterations, double theta)	Create a new layout algorithm
IndexedFRLayoutAlgorithm2D(int iterations, double theta, double normalizationFactor)	Create a new layout algorithm
IndexedFRLayoutAlgorithm2D(int iterations, double theta, double normalizationFactor, Random rng)	Create a new layout algorithm
IndexedFRLayoutAlgorithm2D(int iterations, double theta, double normalizationFactor, Random rng, double tolerance)	Create a new layout algorithm

Method Summary

Modifier and Type	Method	Description
protected Map<V,Point2D>	calculateRepulsiveForces(Graph<V,E> graph, LayoutModel2D<V> model)	Calculate the repulsive forces between vertices
long	getSavedComparisons()	Get the total number of saved comparisons due to the Barnes-Hut technique.
void	layout(Graph<V,E> graph, LayoutModel2D<V> model)	Layout a graph.

Methods inherited from class FRLayoutAlgorithm2D

attractiveForce, calculateAttractiveForces, repulsiveForce

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_THETA_FACTOR

public static final double DEFAULT_THETA_FACTOR

Default $\theta$ value for approximation using the Barnes-Hut technique

See Also:

• Constant Field Values

theta

protected double theta

savedComparisons

protected long savedComparisons

Constructor Details

IndexedFRLayoutAlgorithm2D

public IndexedFRLayoutAlgorithm2D()

Create a new layout algorithm

IndexedFRLayoutAlgorithm2D

public IndexedFRLayoutAlgorithm2D(int iterations,
 double theta)

Create a new layout algorithm

Parameters:

iterations - number of iterations

theta - parameter for approximation using the Barnes-Hut technique

IndexedFRLayoutAlgorithm2D

public IndexedFRLayoutAlgorithm2D(int iterations,
 double theta,
 double normalizationFactor)

Create a new layout algorithm

Parameters:

iterations - number of iterations

theta - parameter for approximation using the Barnes-Hut technique

normalizationFactor - normalization factor for the optimal distance

IndexedFRLayoutAlgorithm2D

public IndexedFRLayoutAlgorithm2D(int iterations,
 double theta,
 double normalizationFactor,
 Random rng)

Create a new layout algorithm

Parameters:

iterations - number of iterations

theta - theta parameter for the Barnes-Hut approximation

normalizationFactor - normalization factor for the optimal distance

rng - the random number generator

IndexedFRLayoutAlgorithm2D

public IndexedFRLayoutAlgorithm2D(int iterations,
 double theta,
 double normalizationFactor,
 Random rng,
 double tolerance)

Create a new layout algorithm

Parameters:

iterations - number of iterations

theta - theta parameter for the Barnes-Hut approximation

normalizationFactor - normalization factor for the optimal distance

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.

Specified by:

layout in interface LayoutAlgorithm2D<V,E>

Overrides:

layout in class FRLayoutAlgorithm2D<V,E>

Parameters:

graph - the graph

model - the layout model to use

calculateRepulsiveForces

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

Description copied from class: FRLayoutAlgorithm2D

Calculate the repulsive forces between vertices

Overrides:

calculateRepulsiveForces in class FRLayoutAlgorithm2D<V,E>

Parameters:

graph - the graph

model - the model

Returns:

the displacement per vertex due to the repulsive forces

getSavedComparisons

public long getSavedComparisons()

Get the total number of saved comparisons due to the Barnes-Hut technique.

Returns:

the total number of saved comparisons