com.google.maps.android.clustering.algo

Class NonHierarchicalDistanceBasedAlgorithm<T extends ClusterItem>

java.lang.Object

com.google.maps.android.clustering.algo.AbstractAlgorithm<T>

com.google.maps.android.clustering.algo.NonHierarchicalDistanceBasedAlgorithm<T>

All Implemented Interfaces:

Algorithm<T>

Direct Known Subclasses:

NonHierarchicalViewBasedAlgorithm

public class NonHierarchicalDistanceBasedAlgorithm<T extends ClusterItem>
extends AbstractAlgorithm<T>

A simple clustering algorithm with O(nlog n) performance. Resulting clusters are not hierarchical.

High level algorithm:
1. Iterate over items in the order they were added (candidate clusters).
2. Create a cluster with the center of the item.
3. Add all items that are within a certain distance to the cluster.
4. Move any items out of an existing cluster if they are closer to another cluster.
5. Remove those items from the list of candidate clusters.

Clusters have the center of the first element (not the centroid of the items within it).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	NonHierarchicalDistanceBasedAlgorithm.QuadItem<T extends ClusterItem>

Constructor Summary

Constructors

Constructor and Description
NonHierarchicalDistanceBasedAlgorithm()

Method Summary

Modifier and Type	Method and Description
boolean	addItem(T item) Adds an item to the algorithm
boolean	addItems(java.util.Collection<T> items) Adds a collection of items to the algorithm
void	clearItems()
protected java.util.Collection<NonHierarchicalDistanceBasedAlgorithm.QuadItem<T>>	getClusteringItems(PointQuadTree<NonHierarchicalDistanceBasedAlgorithm.QuadItem<T>> quadTree, float zoom)
java.util.Set<? extends Cluster<T>>	getClusters(float zoom)
java.util.Collection<T>	getItems()
int	getMaxDistanceBetweenClusteredItems()
boolean	removeItem(T item) Removes an item from the algorithm
boolean	removeItems(java.util.Collection<T> items) Removes a collection of items from the algorithm
void	setMaxDistanceBetweenClusteredItems(int maxDistance)
boolean	updateItem(T item) Updates the provided item in the algorithm

Methods inherited from class com.google.maps.android.clustering.algo.AbstractAlgorithm

lock, unlock

Methods inherited from class java.lang.Object

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

Constructor Detail

NonHierarchicalDistanceBasedAlgorithm

public NonHierarchicalDistanceBasedAlgorithm()

Method Detail

addItem

public boolean addItem(T item)

Adds an item to the algorithm

Parameters:

item - the item to be added

Returns:

true if the algorithm contents changed as a result of the call

addItems

public boolean addItems(java.util.Collection<T> items)

Adds a collection of items to the algorithm

Parameters:

items - the items to be added

Returns:

true if the algorithm contents changed as a result of the call

clearItems

public void clearItems()

removeItem

public boolean removeItem(T item)

Removes an item from the algorithm

Parameters:

item - the item to be removed

Returns:

true if this algorithm contained the specified element (or equivalently, if this algorithm changed as a result of the call).

removeItems

public boolean removeItems(java.util.Collection<T> items)

Removes a collection of items from the algorithm

Parameters:

items - the items to be removed

Returns:

true if this algorithm contents changed as a result of the call

updateItem

public boolean updateItem(T item)

Updates the provided item in the algorithm

Parameters:

item - the item to be updated

Returns:

true if the item existed in the algorithm and was updated, or false if the item did not exist in the algorithm and the algorithm contents remain unchanged.

getClusters

public java.util.Set<? extends Cluster<T>> getClusters(float zoom)

getClusteringItems

protected java.util.Collection<NonHierarchicalDistanceBasedAlgorithm.QuadItem<T>> getClusteringItems(PointQuadTree<NonHierarchicalDistanceBasedAlgorithm.QuadItem<T>> quadTree,
                                                                                                     float zoom)

getItems

public java.util.Collection<T> getItems()

setMaxDistanceBetweenClusteredItems

public void setMaxDistanceBetweenClusteredItems(int maxDistance)

getMaxDistanceBetweenClusteredItems

public int getMaxDistanceBetweenClusteredItems()