Package org.tinspin.index.qtplain

Class QuadTreeKD0<T>

java.lang.Object

org.tinspin.index.qtplain.QuadTreeKD0<T>

Type Parameters:

T - Value type.

All Implemented Interfaces:

Index, PointMap<T>, PointMultimap<T>

public class QuadTreeKD0<T>
extends Object
implements PointMap<T>, PointMultimap<T>

A simple MX-quadtree implementation with configurable maximum depth, maximum nodes size, and (if desired) automatic guessing of root rectangle.

This version of the quadtree stores for each node only the center point and the distance (radius) to the edges. This reduces space requirements but increases problems with numerical precision. Overall it is more space efficient and slightly faster.

Author:

ztilmann

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	QuadTreeKD0.QIterator<T>	Resettable query iterator.
static class	QuadTreeKD0.QStats	Statistics container class.

Nested classes/interfaces inherited from interface org.tinspin.index.Index

Index.BEComparator, Index.BoxEntry<T>, Index.BoxEntryKnn<T>, Index.BoxFilterKnn<T>, Index.BoxIterator<T>, Index.BoxIteratorKnn<T>, Index.PEComparator, Index.PointEntry<T>, Index.PointEntryKnn<T>, Index.PointFilterKnn<T>, Index.PointIterator<T>, Index.PointIteratorKnn<T>, Index.QueryIterator<T>, Index.QueryIteratorKnn<T>

Nested classes/interfaces inherited from interface org.tinspin.index.PointMap

PointMap.Factory

Nested classes/interfaces inherited from interface org.tinspin.index.PointMultimap

PointMultimap.Factory

Field Summary

Fields

Modifier and Type	Field	Description
static boolean	DEBUG

Method Summary

Modifier and Type	Method	Description
void	clear()	Removes all elements from the tree.
boolean	contains(double[] key)	Deprecated.
boolean	contains(double[] key, T value)	Lookup an entry, using exact match.
static <T> QuadTreeKD0<T>	create(int dims)
static <T> QuadTreeKD0<T>	create(int dims, int maxNodeSize)
static <T> QuadTreeKD0<T>	create(int dims, int maxNodeSize, double[] center, double radius)
int	getDepth()
int	getDims()
int	getNodeCount()
QuadTreeKD0.QStats	getStats()
void	insert(double[] key, T value)	Insert a key-value pair.
Index.PointIterator<T>	iterator()
QuadTreeKD0.QIterator<T>	query(double[] min, double[] max)	Query the tree, returning all points in the axis-aligned rectangle between 'min' and 'max'.
Index.PointEntryKnn<T>	query1nn(double[] center)	Finds the nearest neighbor.
T	queryExact(double[] key)	Get the value associates with the key.
Index.PointIterator<T>	queryExactPoint(double[] point)	Lookup an entries at a given coordinate.
Index.PointIteratorKnn<T>	queryKnn(double[] center, int k)	Finds the nearest neighbor.
Index.PointIteratorKnn<T>	queryKnn(double[] center, int k, PointDistance dist)	Finds the nearest neighbor.
T	remove(double[] key)	Remove a key.
boolean	remove(double[] key, T value)	Remove *one* entry with the given value.
boolean	removeIf(double[] key, Predicate<Index.PointEntry<T>> condition)	Remove *one* entry with the given condition.
int	size()	Get the number of key-value pairs in the tree.
String	toString()
String	toStringTree()	Returns a printable list of the tree.
T	update(double[] oldKey, double[] newKey)	Reinsert the key.
boolean	update(double[] oldKey, double[] newKey, T value)	Reinsert the key.
T	updateIf(double[] oldKey, double[] newKey, Predicate<Index.PointEntry<T>> condition)	Reinsert the key.

Methods inherited from class java.lang.Object

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

Field Detail

DEBUG

public static final boolean DEBUG

See Also:

Constant Field Values

Method Detail

create

public static <T> QuadTreeKD0<T> create(int dims)

create

public static <T> QuadTreeKD0<T> create(int dims,
                                        int maxNodeSize)

create

public static <T> QuadTreeKD0<T> create(int dims,
                                        int maxNodeSize,
                                        double[] center,
                                        double radius)

insert

public void insert(double[] key,
                   T value)

Insert a key-value pair.

Specified by:

insert in interface PointMap<T>

Specified by:

insert in interface PointMultimap<T>

Parameters:

key - the key

value - the value

contains

@Deprecated
public boolean contains(double[] key)

Deprecated.

Check whether a given key exists.

Specified by:

contains in interface PointMap<T>

Parameters:

key - the key to check

Returns:

true iff the key exists

queryExact

public T queryExact(double[] key)

Get the value associates with the key.

Specified by:

queryExact in interface PointMap<T>

Parameters:

key - the key to look up

Returns:

the value for the key or 'null' if the key was not found

contains

public boolean contains(double[] key,
                        T value)

Description copied from interface: PointMultimap

Lookup an entry, using exact match.

Specified by:

contains in interface PointMultimap<T>

Parameters:

key - the point

value - the value

Returns:

`true` if an entry was found, otherwise `false`.

remove

public T remove(double[] key)

Remove a key.

Specified by:

remove in interface PointMap<T>

Parameters:

key - key to remove

Returns:

the value associated with the key or 'null' if the key was not found

remove

public boolean remove(double[] key,
                      T value)

Description copied from interface: PointMultimap

Remove *one* entry with the given value.

Specified by:

remove in interface PointMultimap<T>

Parameters:

key - the point

value - only entries with this value are removed

Returns:

the value of the entry or null if the entry was not found

removeIf

public boolean removeIf(double[] key,
                        Predicate<Index.PointEntry<T>> condition)

Description copied from interface: PointMultimap

Remove *one* entry with the given condition.

Specified by:

removeIf in interface PointMultimap<T>

Parameters:

key - the point

condition - the condition required for removing an entry

Returns:

the value of the entry or null if the entry was not found

update

public T update(double[] oldKey,
                double[] newKey)

Reinsert the key.

Specified by:

update in interface PointMap<T>

Parameters:

oldKey - old key

newKey - new key

Returns:

the value associated with the key or 'null' if the key was not found.

update

public boolean update(double[] oldKey,
                      double[] newKey,
                      T value)

Reinsert the key.

Specified by:

update in interface PointMultimap<T>

Parameters:

oldKey - old key

newKey - new key

value - the value of the entry that should be updated.

Returns:

the value associated with the key or 'null' if the key was not found.

updateIf

public T updateIf(double[] oldKey,
                  double[] newKey,
                  Predicate<Index.PointEntry<T>> condition)

Reinsert the key.

Parameters:

oldKey - old key

newKey - new key

condition - A predicate that must evaluate to 'true' for an entry to be updated.

Returns:

the value associated with the key or 'null' if the key was not found.

size

public int size()

Get the number of key-value pairs in the tree.

Specified by:

size in interface Index

Returns:

the size

clear

public void clear()

Removes all elements from the tree.

Specified by:

clear in interface Index

queryExactPoint

public Index.PointIterator<T> queryExactPoint(double[] point)

Description copied from interface: PointMultimap

Lookup an entries at a given coordinate.

Specified by:

queryExactPoint in interface PointMultimap<T>

Parameters:

point - the point

Returns:

an iterator over all entries at the given coordinate.

See Also:

PointMultimap.queryExactPoint(double[])

query

public QuadTreeKD0.QIterator<T> query(double[] min,
                                      double[] max)

Query the tree, returning all points in the axis-aligned rectangle between 'min' and 'max'.

Specified by:

query in interface PointMap<T>

Specified by:

query in interface PointMultimap<T>

Parameters:

min - lower left corner of query

max - upper right corner of query

Returns:

all entries in the rectangle

query1nn

public Index.PointEntryKnn<T> query1nn(double[] center)

Description copied from interface: PointMap

Finds the nearest neighbor. This uses Euclidean distance. Other distance types can only be specified directly on the index implementations.

Specified by:

query1nn in interface PointMap<T>

Specified by:

query1nn in interface PointMultimap<T>

Parameters:

center - center point

Returns:

the nearest neighbor

queryKnn

public Index.PointIteratorKnn<T> queryKnn(double[] center,
                                          int k,
                                          PointDistance dist)

Description copied from interface: PointMultimap

Finds the nearest neighbor. This uses Euclidean distance. Other distance types can only be specified directly on the index implementations.

Specified by:

queryKnn in interface PointMultimap<T>

Parameters:

center - center point

k - number of neighbors

dist - the point distance function to be used

Returns:

Iterator over query result

See Also:

PointMultimap.queryKnn(double[], int, PointDistance)

toStringTree

public String toStringTree()

Returns a printable list of the tree.

Specified by:

toStringTree in interface Index

Returns:

the tree as String

toString

public String toString()

Overrides:

toString in class Object

getStats

public QuadTreeKD0.QStats getStats()

Specified by:

getStats in interface Index

Returns:

Collect and return some index statistics. Note that indexes are not required to fill all fields. Also, individual indexes may use subclasses with additional fields.

getDims

public int getDims()

Specified by:

getDims in interface Index

Returns:

the number of dimensions

iterator

public Index.PointIterator<T> iterator()

Specified by:

iterator in interface PointMap<T>

Specified by:

iterator in interface PointMultimap<T>

Returns:

An iterator over all entries.

queryKnn

public Index.PointIteratorKnn<T> queryKnn(double[] center,
                                          int k)

Description copied from interface: PointMap

Finds the nearest neighbor. This uses Euclidean distance. Other distance types can only be specified directly on the index implementations.

Specified by:

queryKnn in interface PointMap<T>

Specified by:

queryKnn in interface PointMultimap<T>

Parameters:

center - center point

k - number of neighbors

Returns:

list of nearest neighbors

getNodeCount

public int getNodeCount()

Specified by:

getNodeCount in interface Index

getDepth

public int getDepth()

Specified by:

getDepth in interface Index