java.lang.Object
- org.tinspin.index.qthypercube2.QuadTreeKD2<T>

Type Parameters:

T - Value type.

All Implemented Interfaces:

Index, PointMap<T>, PointMultimap<T>
```
public class QuadTreeKD2<T>
extends Object
implements PointMap<T>, PointMultimap<T>
```
This is a MX-quadtree implementation with configurable maximum depth, maximum nodes size, and (if desired) automatic guessing of root rectangle. For navigation during insert/delete/update/queries, it uses hypercube navigation as described by T. Zaeschke and M. Norrie, "Efficient Z-Ordered Traversal of Hypercube Indexes, BTW proceedings, 2017. 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. This version 2 of the QuadtreeHC reduces memory consumption allowing directory nodes to contain data entries. With version 1, there were many nodes with just one data entry because the parent directory node could not hold date entries. With version two a directory node (which contains a hypercube array) will only create a subnode if a quadrant has to mhold more than one data entry.

Author:

ztilmann

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class QuadTreeKD2.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`
`static boolean`	`ENABLE_HCI_1`	Enable basic HCI navigation with Algo #1 isInI(), for example for window queries.
`static boolean`	`ENABLE_HCI_2`	Enable basic HCI navigation with Algo #2 inc(), for example for window queries.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`clear()`	Removes all elements from the tree.
`boolean`	`contains(double[] key)`	Check whether a given key exists.
`boolean`	`contains(double[] key, T value)`	Lookup an entry, using exact match.
`static <T> QuadTreeKD2<T>`	`create(int dims)`
`static <T> QuadTreeKD2<T>`	`create(int dims, int maxNodeSize)`
`static <T> QuadTreeKD2<T>`	`create(int dims, int maxNodeSize, double[] center, double radius)`
`int`	`getDepth()`
`int`	`getDims()`
`int`	`getNodeCount()`
`protected QNode<T>`	`getRoot()`
`QuadTreeKD2.QStats`	`getStats()`
`void`	`insert(double[] key, T value)`	Insert a key-value pair.
`Index.PointIterator<T>`	`iterator()`
`Index.PointIterator<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 distFn)`	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
  - ENABLE_HCI_1
```
public static boolean ENABLE_HCI_1
```
    Enable basic HCI navigation with Algo #1 isInI(), for example for window queries.
  - ENABLE_HCI_2
```
public static boolean ENABLE_HCI_2
```
    Enable basic HCI navigation with Algo #2 inc(), for example for window queries.
  - DEBUG
```
public static final boolean DEBUG
```
    See Also:
    
    Constant Field Values
- Method Detail
  - create
```
public static <T> QuadTreeKD2<T> create(int dims)
```
  - create
```
public static <T> QuadTreeKD2<T> create(int dims,
                                        int maxNodeSize)
```
  - create
```
public static <T> QuadTreeKD2<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
```
public boolean contains(double[] key)
```
    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 Index.PointIterator<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 distFn)
```
    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
    
    distFn - 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 QuadTreeKD2.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
  - getRoot
```
protected QNode<T> getRoot()
```

Class QuadTreeKD2<T>

Nested Class Summary

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

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

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

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ENABLE_HCI_1

ENABLE_HCI_2

DEBUG

Method Detail

create

create

create

insert

contains

queryExact

contains

remove

remove

removeIf

update

update

updateIf

size

clear

queryExactPoint

query

query1nn

queryKnn

toStringTree

toString

getStats

getDims

iterator

queryKnn

getNodeCount

getDepth

getRoot