KNNHeap (ELKI: Environment for DeveLoping KDD-Applications Supported by Index-Structures)

All Known Implementing Classes:

DoubleIntegerDBIDKNNHeap, DoubleIntegerDBIDListKNNHeap, DoubleIntegerDBIDPairKNNListHeap
```
public interface KNNHeap
```
Interface for kNN heaps. To instantiate, use: DBIDUtil.newHeap(int)!

Author:

Erich Schubert

Method Summary

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

- Method Detail
  - toKNNList
```
KNNList 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
```
double getKNNDistance()
```
    Get the distance to the k nearest neighbor, or maxdist otherwise.
    
    Returns:
    Maximum distance
  - insert
```
double insert(double 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
    
    Returns:
    current k-distance
  - insert
```
void insert(DoubleDBIDPair e)
```
    Add a distance-id pair to the heap unless the distance is too large. Use for existing pairs.
    
    Parameters:
    e - Existing distance pair
  - 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
```
DoubleDBIDPair 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
```
DoubleDBIDPair peek()
```
    Peek at the largest element in the heap.
    
    Returns:
    The current largest element.

Interface KNNHeap

Method Summary

Method Detail

toKNNList

getK

getKNNDistance

insert

insert

size

isEmpty

clear

poll

peek