oracle.spatial.util
Class RTree

java.lang.Object
oracle.spatial.util.RTree

All Implemented Interfaces:

java.io.Serializable

public class RTree

extends java.lang.Object

implements java.io.Serializable

See Also:

Serialized Form

Nested Class Summary

class	RTree.ComparatorImpl
class	RTree.RTreePlot

Field Summary

protected int	entryCount
protected int	leafCount
protected int	levels
protected oracle.spatial.util.RTree.Span[]	mbh
protected int	minFill
protected int	nDimensions
protected int	nodeCount
protected int	nodeSize
protected oracle.spatial.util.RTree.TreeNode	root

Constructor Summary

RTree(int nD, int nS, int mF)
Constructs an empty RTree with specified parameters

Method Summary

void	addEntry(double[][] h, java.lang.Object o) addEntry adds an entry at leaf level to the RTree.
int	getEntryCount() Gets the number of entries (inserted objects) in the tree
double[][]	getMBH() Gets the bounds of the whole tree
static void	main(java.lang.String[] args)
void	packTree(double[][][] mbhList, java.lang.Object[] pList) Generates a highly ordered packed tree using the scan-tile-recursive method
boolean	removeEntry(double[][] h, java.lang.Object o) removeEntry removes an entry from the leaf level of the RTree and makes any other tree adjustments necessary, including possibly the orphaning and reinsertion of subtrees at any level if nodes become underfilled
boolean	search(double[][] h, java.util.ArrayList a) Searches an RTree for all objects whose minimum bounding hypersolids intersect the input search hypersolid
void	showRTreePlot()
void	showRTreePlot(java.lang.String title)

Methods inherited from class java.lang.Object

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

Field Detail

nDimensions

protected int nDimensions

nodeSize

protected int nodeSize

minFill

protected int minFill

nodeCount

protected int nodeCount

leafCount

protected int leafCount

entryCount

protected int entryCount

levels

protected int levels

mbh

protected oracle.spatial.util.RTree.Span[] mbh

root

protected oracle.spatial.util.RTree.TreeNode root

Constructor Detail

RTree

public RTree(int nD,
             int nS,
             int mF)

Constructs an empty RTree with specified parameters

Parameters:

nD - Number of dimensions in the space indexed by the tree. Can be 1, 2, 3,...

nS - Node size; the number of entries per node. Since this is a RAM- resident tree there is no need to match node size with disk pages and node sizes of 5-12 will give best results

mF - Minimum fill - the number of entries in a node below which the node is considered underfull and the remaining entries orphaned and reinserted in the tree. If set to 1, there will be no orphaning

Method Detail

getMBH

public double[][] getMBH()

Gets the bounds of the whole tree

Returns:

an 2-dimensional array of doubles where the first index ranges over [0,nDim-1], the dimension of the indexed space and the second index ranges over [0,1], the min and max on each dimension

getEntryCount

public int getEntryCount()

Gets the number of entries (inserted objects) in the tree

Returns:

the number of entries at leaf level of the tree

search

public boolean search(double[][] h,
                      java.util.ArrayList a)

Searches an RTree for all objects whose minimum bounding hypersolids intersect the input search hypersolid

Parameters:

h - two dimensional array of doubles which are the minimum bounding hypersolid defining the search. The first index ranges over 0,nDimensions-1 and is the dimension of the space. The second index ranges over 0,1 and specifies the min and max.

a - The ArrayList holds the objects found to satisfy the search. Should be preallocated by the caller and set via the constructor or ensureCapacity(int) for expected result size (for efficiency). Will not overflow if undersized.

Returns:

true if there are some results of the search; false if none. ArrayList a.size() will return the number of hits.

addEntry

public void addEntry(double[][] h,
                     java.lang.Object o)

addEntry adds an entry at leaf level to the RTree.

Parameters:

h - two dimensional array of doubles defining the minimum bounding hypersolid of the added object. The first index ranges over 0,nDim-1 where nDim is the dimension of the space (1,2,3...). The second index ranges over 0,1 and selects the min and max

o - The inserted Object reference

removeEntry

public boolean removeEntry(double[][] h,
                           java.lang.Object o)

removeEntry removes an entry from the leaf level of the RTree and makes any other tree adjustments necessary, including possibly the orphaning and reinsertion of subtrees at any level if nodes become underfilled

Parameters:

h - two dimensional array of doubles defining the minimum bounding hypersolid of the removed object. The first index ranges over 0,nDimensions-1 and is the dimension of the space. The second index ranges over 0,1 and specifies the min or max

o - The removed Object reference

Returns:

true if the object was found and removed; false if not in tree

packTree

public void packTree(double[][][] mbhList,
                     java.lang.Object[] pList)
              throws java.lang.Exception

Generates a highly ordered packed tree using the scan-tile-recursive method

Parameters:

mbhList - A list of mbh objects which is a three dimensional array of doubles. The first index ranges over 0,num-1 of entries. The second index ranges over 0,ndim-1 the size of the space The third index ranges over 0,1 for min, max.

pList - An array of Object references. The length of the array is the same as the number of entries in the array of MBHs (the first index).

Throws:

java.lang.Exception

main

public static void main(java.lang.String[] args)
                 throws java.io.IOException,
                        java.lang.Exception

Throws:

java.io.IOException

java.lang.Exception

showRTreePlot

public void showRTreePlot(java.lang.String title)

showRTreePlot

public void showRTreePlot()