程序包 org.meteoinfo.math.stats.kde.kdtree

类 KDTree

java.lang.Object

org.meteoinfo.math.stats.kde.kdtree.KDTree

所有已实现的接口:

Serializable

public class KDTree
extends Object
implements Serializable

KDTree is a class supporting KD-tree insertion, deletion, equality search, range search, and nearest neighbor(s) using double-precision floating-point keys. Splitting dimension is chosen naively, by depth modulo K. Semantics are as follows:

• Two different keys containing identical numbers should retrieve the same value from a given KD-tree. Therefore keys are cloned when a node is inserted.
  
  
• As with Hashtables, values inserted into a KD-tree are not cloned. Modifying a value between insertion and retrieval will therefore modify the value stored in the tree.

从以下版本开始:

JDK1.2

版本:

%I%, %G%

作者:

Simon Levy, Bjoern Heckel

另请参阅:

序列化表格

构造器概要

构造器

构造器	说明
KDTree(int k)	Creates a KD-tree with specified number of dimensions.

方法概要

限定符和类型	方法	说明
void	delete(double[] key)	Delete a node from a KD-tree.
void	insert(double[] key, Object value)	Insert a node in a KD-tree.
Object	nearest(double[] key)	Find KD-tree node whose key is nearest neighbor to key.
Object[]	nearest(double[] key, int n)	Find KD-tree nodes whose keys are n nearest neighbors to key.
Object[]	range(double[] lowk, double[] uppk)	Range search in a KD-tree.
Object	search(double[] key)	Find KD-tree node whose key is identical to key.
String	toString()

从类继承的方法 java.lang.Object

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

构造器详细资料

KDTree

public KDTree(int k)

Creates a KD-tree with specified number of dimensions.

参数:

k - number of dimensions

方法详细资料

insert

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

Insert a node in a KD-tree. Uses algorithm translated from 352.ins.c of

   @Book{GonnetBaezaYates1991,                                   
     author =    {G.H. Gonnet and R. Baeza-Yates},
     title =     {Handbook of Algorithms and Data Structures},
     publisher = {Addison-Wesley},
     year =      {1991}
   }
 

参数:

key - key for KD-tree node

value - value at that key

抛出:

KeySizeException - if key.length mismatches K

KeyDuplicateException - if key already in tree

search

public Object search(double[] key)

Find KD-tree node whose key is identical to key. Uses algorithm translated from 352.srch.c of Gonnet & Baeza-Yates.

参数:

key - key for KD-tree node

返回:

object at key, or null if not found

抛出:

KeySizeException - if key.length mismatches K

delete

public void delete(double[] key)

Delete a node from a KD-tree. Instead of actually deleting node and rebuilding tree, marks node as deleted. Hence, it is up to the caller to rebuild the tree as needed for efficiency.

参数:

key - key for KD-tree node

抛出:

KeySizeException - if key.length mismatches K

KeyMissingException - if no node in tree has key

nearest

public Object nearest(double[] key)

Find KD-tree node whose key is nearest neighbor to key. Implements the Nearest Neighbor algorithm (Table 6.4) of

 @techreport{AndrewMooreNearestNeighbor,
   author  = {Andrew Moore},
   title   = {An introductory tutorial on kd-trees},
   institution = {Robotics Institute, Carnegie Mellon University},
   year    = {1991},
   number  = {Technical Report No. 209, Computer Laboratory, 
              University of Cambridge},
   address = {Pittsburgh, PA}
 }
 

参数:

key - key for KD-tree node

返回:

object at node nearest to key, or null on failure

抛出:

KeySizeException - if key.length mismatches K

nearest

public Object[] nearest(double[] key,
                        int n)

Find KD-tree nodes whose keys are n nearest neighbors to key. Uses algorithm above. Neighbors are returned in ascending order of distance to key.

参数:

key - key for KD-tree node

n - how many neighbors to find

返回:

objects at node nearest to key, or null on failure

抛出:

KeySizeException - if key.length mismatches K

IllegalArgumentException - if n is negative or exceeds tree size

range

public Object[] range(double[] lowk,
                      double[] uppk)

Range search in a KD-tree. Uses algorithm translated from 352.range.c of Gonnet & Baeza-Yates.

参数:

lowk - lower-bounds for key

uppk - upper-bounds for key

返回:

array of Objects whose keys fall in range [lowk,uppk]

抛出:

KeySizeException - on mismatch among lowk.length, uppk.length, or K

toString

public String toString()

覆盖:

toString 在类中 Object