de.lmu.ifi.dbs.elki.database.ids.distance

Interface KNNHeap<D extends Distance<D>>

Type Parameters:

D - Distance function

All Known Subinterfaces:

DoubleDistanceKNNHeap

All Known Implementing Classes:

AbstractKNNHeap, DistanceDBIDPairKNNHeap, DoubleDistanceDBIDPairKNNHeap, DoubleDistanceIntegerDBIDKNNHeap, DoubleDistanceIntegerDBIDKNNListHeap

public interface KNNHeap<D extends Distance<D>>

Interface for kNN heaps. To instantiate, use: DBIDUtil.newHeap(D, int)!

Method Summary

Methods

Modifier and Type	Method and Description
void	add(D distance, DBIDRef id) Add a distance-id pair to the heap unless the distance is too large.
void	clear() Clear the heap.
int	getK() Get the K parameter ("maxsize" internally).
D	getKNNDistance() Get the distance to the k nearest neighbor, or maxdist otherwise.
boolean	isEmpty() Test if the heap is empty.
DistanceDBIDPair<D>	peek() Peek at the largest element in the heap.
DistanceDBIDPair<D>	poll() Poll the largest element from the heap.
int	size() Current size of heap.
KNNList<D>	toKNNList() Serialize to a KNNList.

Method Detail

toKNNList

KNNList<D> toKNNList()

Serialize to a KNNList. This empties the heap!

Returns:

KNNList with the heaps contents.

getK

int getK()

Get the K parameter ("maxsize" internally).

Returns:

K

getKNNDistance

D getKNNDistance()

Get the distance to the k nearest neighbor, or maxdist otherwise.

Returns:

Maximum distance

add

void add(D distance,
       DBIDRef id)

Add a distance-id pair to the heap unless the distance is too large. Compared to the super.add() method, this often saves the pair construction.

Parameters:

distance - Distance value

id - ID number

size

int size()

Current size of heap.

Returns:

Heap size

isEmpty

boolean isEmpty()

Test if the heap is empty.

Returns:

true when empty.

clear

void clear()

Clear the heap.

poll

DistanceDBIDPair<D> poll()

Poll the largest element from the heap. This is in descending order because of the heap structure. For a convenient way to serialize the heap into a list that you can iterate in ascending order, see toKNNList().

Returns:

largest element

peek

DistanceDBIDPair<D> peek()

Peek at the largest element in the heap.

Returns:

The current largest element.