BarnesHutQuadTree (JunGrapht Visualization 1.1 API)

java.lang.Object
- org.jungrapht.visualization.layout.quadtree.BarnesHutQuadTree<T>

```
public class BarnesHutQuadTree<T>
extends Object
```
A QuadTree that can gather combined forces from visited nodes. Inspired by http://arborjs.org/docs/barnes-hut http://www.cs.princeton.edu/courses/archive/fall03/cs126/assignments/barnes-hut.html https://github.com/chindesaurus/BarnesHut-N-Body

Author:

Tom Nelson

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class BarnesHutQuadTree.Builder<T>

Constructor Summary

Constructors
Constructor Description

BarnesHutQuadTree()

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`applyForcesTo(ForceObject<T> visitor)`
`static <T> BarnesHutQuadTree.Builder<T>`	`builder()`
`void`	`clear()`
`Rectangle`	`getBounds()`	the bounds of this quad tree
`Node<T>`	`getRoot()`
`protected void`	`insert(ForceObject node)`
`void`	`rebuild(Collection<T> elements, Function<T,Double> masses, Function<T,Point> locations)`
`void`	`rebuild(Collection<T> elements, Function<T,Point> locations)`	rebuild the quad tree with the nodes and location mappings of the passed LayoutModel
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail
- BarnesHutQuadTree
```
public BarnesHutQuadTree()
```

Method Detail

builder

public static <T> BarnesHutQuadTree.Builder<T> builder()

getBounds
```
public Rectangle getBounds()
```
the bounds of this quad tree

Returns:

the bounds of the entire quadtree

getRoot
```
public Node<T> getRoot()
```
Returns:

the root Node of this tree

clear
```
public void clear()
```

applyForcesTo
```
public void applyForcesTo(ForceObject<T> visitor)
```
Parameters:

visitor - passed ForceObject will visit nodes in the quad tree and accumulate their forces

insert

protected void insert(ForceObject node)

rebuild
```
public void rebuild(Collection<T> elements,
                    Function<T,Point> locations)
```
rebuild the quad tree with the nodes and location mappings of the passed LayoutModel

Parameters:

locations - - mapping of elements to locations

rebuild

public void rebuild(Collection<T> elements,
                    Function<T,Double> masses,
                    Function<T,Point> locations)

toString
```
public String toString()
```
Overrides:

toString in class Object