Package elki.database.ids

Interface DoubleDBIDHeap

All Superinterfaces:

DBIDRef

All Known Subinterfaces:

KNNHeap

All Known Implementing Classes:

DoubleIntegerDBIDHeap, DoubleIntegerDBIDKNNHeap

public interface DoubleDBIDHeap
extends DBIDRef

Max heap for DBIDs.

To instantiate, use: DBIDUtil.newMaxHeap(int)!

Since:

0.5.5

Author:

Erich Schubert

Method Summary

Modifier and Type	Method	Description
void	clear()	Clear the heap.
boolean	contains(DBIDRef other)	Check if an object is already in the heap (slow scan).
double	insert(double key, DBIDRef id)	Add a double-id pair to the heap
double	insert(double distance, DBIDRef id, int max)	Add a double-id pair to the heap unless the heap grows beyond the given maximum size.
default boolean	isEmpty()	Test if the heap is empty.
double	peekKey()	Get the topmost value (the heap is a DBIDRef, referencing the top element).
void	poll()	Remove the topmost element.
int	size()	Current size of heap.
DoubleDBIDIter	unorderedIterator()	Unordered iterator over the heap.

Methods inherited from interface elki.database.ids.DBIDRef

equals, hashCode, internalGetIndex

Method Detail

peekKey

double peekKey()

Get the topmost value (the heap is a DBIDRef, referencing the top element).

Returns:

value at top

poll

void poll()

Remove the topmost element.

insert

double insert(double key,
              DBIDRef id)

Add a double-id pair to the heap

Parameters:

key - Key value

id - ID number

Returns:

Value of to the element at the top of the heap

insert

double insert(double distance,
              DBIDRef id,
              int max)

Add a double-id pair to the heap unless the heap grows beyond the given maximum size. Beware of the following subtle details:

• If the heap has fewer than "max" elements, the value is added.
• else, if the new value is "worse" than the top, it will replace the top (and the heap will be repaired)
• for a min heap, this adds only larger value, for a max heap only smaller values. This may seem odd, but it is equivalent to adding the new element and then removing the top ("best") element.
• But: the heap will not be reduced to the given size

Parameters:

distance - Distance value

id - ID number

max - Maximum number of values

Returns:

Distance to the element at the top of the heap

size

int size()

Current size of heap.

Returns:

Heap size

isEmpty

default boolean isEmpty()

Test if the heap is empty.

Returns:

true when empty.

clear

void clear()

Clear the heap.

unorderedIterator

DoubleDBIDIter unorderedIterator()

Unordered iterator over the heap.

Returns:

Iterator

contains

boolean contains(DBIDRef other)

Check if an object is already in the heap (slow scan).

Parameters:

other - Other object

Returns:

true if contained