org.tinspin.index.rtree

Class RTree<T>

java.lang.Object

org.tinspin.index.rtree.RTree<T>

Type Parameters:

T - Value type.

All Implemented Interfaces:

Index<T>, RectangleIndex<T>

public class RTree<T>
extends Object
implements RectangleIndex<T>

R*Tree implementation based on the paper from Beckmann, N.; Kriegel, H. P.; Schneider, R.; Seeger, B. (1990). "The R*-tree: an efficient and robust access method for points and rectangles". Revised R*Tree (for DBMS, see conclusion?) -- RR*Tree "A Revised R*-tree in Comparison with Related Index Structures" Norbert Beckmann; Bernhard Seeger Interesting comparison: http://www.boost.org/doc/libs/1_58_0/libs/geometry/doc/html/geometry/spatial_indexes/introduction.html

Author:

ztilmann

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RTree.RTreeStats

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	DEBUG

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	RTree(int dims) Create an RTree.

Method Summary

Modifier and Type	Method and Description
void	clear() Clear all entries.
static <T> RTree<T>	createRStar(int dims)
int	getDepth()
int	getDims()
int	getNodeCount()
protected org.tinspin.index.rtree.RTreeNode<T>	getRoot()
RTree.RTreeStats	getStats()
void	insert(double[] keyMin, double[] keyMax, T value) Insert a rectangle.
void	insert(double[] point, T value)
void	insert(Entry<T> e) Insert an entry.
RTreeIterator<T>	iterator()
void	load(Entry<T>[] entries)
RectangleEntryDist<T>	query1NN(double[] center) Finds the nearest neighbor.
T	queryExact(double[] min, double[] max) Lookup an entry, using exact match.
RTreeIterator<T>	queryIntersect(double[] min, double[] max)
RTreeQueryKnn<T>	queryKNN(double[] center, int k) Finds the nearest neighbor.
RTreeQueryKnn<T>	queryKNN(double[] center, int k, RectangleDistanceFunction dist)
Iterable<RectangleEntryDist<T>>	queryRangedNearestNeighbor(double[] center, RectangleDistanceFunction dist, RectangleDistanceFunction closestDist, double[] minBound, double[] maxBound)
Iterable<RectangleEntryDist<T>>	queryRangedNearestNeighbor(double[] center, RectangleDistanceFunction dist, RectangleDistanceFunction closestDist, Filter filter) This methods returns an Iterable which returns the nodes by a combined range and nearest number search.
Object	remove(double[] point)
T	remove(double[] min, double[] max) Remove an entry.
int	size()
String	toString()
String	toStringTree()
T	update(double[] lo1, double[] up1, double[] lo2, double[] up2) Update the position of an entry.

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

Constructor Detail

RTree

protected RTree(int dims)

Create an RTree. By default it is an R*tree.

Parameters:

dims - dimensionality

Method Detail

createRStar

public static <T> RTree<T> createRStar(int dims)

getDims

public int getDims()

Specified by:

getDims in interface Index<T>

Returns:

the number of dimensions

size

public int size()

Specified by:

size in interface Index<T>

Returns:

the number of entries

clear

public void clear()

Description copied from interface: Index

Clear all entries.

Specified by:

clear in interface Index<T>

insert

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

insert

public void insert(double[] keyMin,
                   double[] keyMax,
                   T value)

Insert a rectangle.

Specified by:

insert in interface RectangleIndex<T>

Parameters:

keyMin - min

keyMax - max

value - value

insert

public void insert(Entry<T> e)

Insert an entry.

Parameters:

e - the entry

load

public void load(Entry<T>[] entries)

remove

public Object remove(double[] point)

remove

public T remove(double[] min,
                double[] max)

Remove an entry.

Specified by:

remove in interface RectangleIndex<T>

Parameters:

min - min

max - max

Returns:

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

update

public T update(double[] lo1,
                double[] up1,
                double[] lo2,
                double[] up2)

Update the position of an entry.

Specified by:

update in interface RectangleIndex<T>

Parameters:

lo1 - old min

up1 - old max

lo2 - new min

up2 - new max

Returns:

the value, or null if the entries was not found

queryExact

public T queryExact(double[] min,
                    double[] max)

Description copied from interface: RectangleIndex

Lookup an entry, using exact match.

Specified by:

queryExact in interface RectangleIndex<T>

Parameters:

min - minimum corner

max - maximum corner

Returns:

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

iterator

public RTreeIterator<T> iterator()

Specified by:

iterator in interface RectangleIndex<T>

Returns:

An iterator over all entries.

queryIntersect

public RTreeIterator<T> queryIntersect(double[] min,
                                       double[] max)

Specified by:

queryIntersect in interface RectangleIndex<T>

Parameters:

min - Lower left corner of the query window

max - Upper right corner of the query window

Returns:

All rectangles that intersect with the query rectangle.

query1NN

public RectangleEntryDist<T> query1NN(double[] center)

Description copied from interface: RectangleIndex

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

Specified by:

query1NN in interface RectangleIndex<T>

Parameters:

center - center point

Returns:

the nearest neighbor

queryKNN

public RTreeQueryKnn<T> queryKNN(double[] center,
                                 int k)

Description copied from interface: RectangleIndex

Finds the nearest neighbor. This uses euclidean 'edge distance', i.e. the distance to the edge of rectangle. Distance is 0 is the rectangle overlaps with the search point. Other distance types can only be specified directly on the index implementations.

Specified by:

queryKNN in interface RectangleIndex<T>

Parameters:

center - center point

k - number of neighbors

Returns:

list of nearest neighbors

queryKNN

public RTreeQueryKnn<T> queryKNN(double[] center,
                                 int k,
                                 RectangleDistanceFunction dist)

queryRangedNearestNeighbor

public Iterable<RectangleEntryDist<T>> queryRangedNearestNeighbor(double[] center,
                                                                  RectangleDistanceFunction dist,
                                                                  RectangleDistanceFunction closestDist,
                                                                  double[] minBound,
                                                                  double[] maxBound)

queryRangedNearestNeighbor

public Iterable<RectangleEntryDist<T>> queryRangedNearestNeighbor(double[] center,
                                                                  RectangleDistanceFunction dist,
                                                                  RectangleDistanceFunction closestDist,
                                                                  Filter filter)

This methods returns an Iterable which returns the nodes by a combined range and nearest number search. The Iterator supports the Iterator.remove() method.

Parameters:

center - Target position passed as parameter to the distance functions. Can be null if your distance function supports it (like RectangleDistanceFunction.RectangleDist).

dist - Distance function used to compare entries (example: RectangleDistanceFunction.EDGE or RectangleDistanceFunction.CENTER)

closestDist - Distance of the best point in a given rectangle (example: RectangleDistanceFunction.EDGE but *not* RectangleDistanceFunction.CENTER)

filter - Filter to limit the results for range queries (example: new Filter.RectangleIntersectFilter(min, max))

Returns:

An Iterable which lazily calculates the nearest neighbors.

toStringTree

public String toStringTree()

Specified by:

toStringTree in interface Index<T>

Returns:

a full string output of the tree structure with all entries

getStats

public RTree.RTreeStats getStats()

Specified by:

getStats in interface Index<T>

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.

getDepth

public int getDepth()

Specified by:

getDepth in interface Index<T>

getNodeCount

public int getNodeCount()

Specified by:

getNodeCount in interface Index<T>

getRoot

protected org.tinspin.index.rtree.RTreeNode<T> getRoot()

toString

public String toString()

Overrides:

toString in class Object