org.apache.datasketches.theta

Class PairwiseSetOperations

java.lang.Object

org.apache.datasketches.theta.PairwiseSetOperations

public class PairwiseSetOperations
extends Object

Set Operations where the arguments are presented in pairs as in C = Op(A,B). These are stateless operations and the result is returned immediately.

These operations are designed for convenience and accept Sketches that may be either Heap-based or Direct.

Author:

Lee Rhodes

Constructor Summary

Constructors

Constructor and Description
PairwiseSetOperations()

Method Summary

Modifier and Type	Method and Description
static CompactSketch	aNotB(Sketch skA, Sketch skB) This implements a stateless, pair-wise A AND NOT B operation on Sketches that are either Heap-based or Direct.
static CompactSketch	intersect(Sketch skA, Sketch skB) This implements a stateless, pair-wise Intersect operation on sketches that are either Heap-based or Direct.
static CompactSketch	union(CompactSketch skA, CompactSketch skB) This implements a stateless, pair-wise union operation on ordered, CompactSketches that are either Heap-based or Direct.
static CompactSketch	union(CompactSketch skA, CompactSketch skB, int k) This implements a stateless, pair-wise union operation on ordered, CompactSketches that are either Heap-based or Direct.

Methods inherited from class java.lang.Object

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

Constructor Detail

PairwiseSetOperations

public PairwiseSetOperations()

Method Detail

intersect

public static CompactSketch intersect(Sketch skA,
                                      Sketch skB)

This implements a stateless, pair-wise Intersect operation on sketches that are either Heap-based or Direct. If both inputs are null an EmptyCompactSketch is returned.

Parameters:

skA - The first Sketch argument.

skB - The second Sketch argument.

Returns:

the result as an ordered CompactSketch on the heap.

aNotB

public static CompactSketch aNotB(Sketch skA,
                                  Sketch skB)

This implements a stateless, pair-wise A AND NOT B operation on Sketches that are either Heap-based or Direct. If both inputs are null an EmptyCompactSketch is returned.

Parameters:

skA - The first Sketch argument.

skB - The second Sketch argument.

Returns:

the result as an ordered CompactSketch on the heap.

union

public static CompactSketch union(CompactSketch skA,
                                  CompactSketch skB)

This implements a stateless, pair-wise union operation on ordered, CompactSketches that are either Heap-based or Direct. If both inputs are null an EmptyCompactSketch is returned. If one is null the other is returned, which can be either Heap-based or Direct. This is equivalent to union(skA, skB, k) where k is the default of 4096.

Parameters:

skA - The first ordered, CompactSketch argument.

skB - The second ordered, CompactSketch argument

Returns:

the result as an ordered CompactSketch.

union

public static CompactSketch union(CompactSketch skA,
                                  CompactSketch skB,
                                  int k)

This implements a stateless, pair-wise union operation on ordered, CompactSketches that are either Heap-based or Direct. The returned sketch will be cutback to k if required, similar to the regular Union operation. If a cutback is required, the returned sketch will always be on the heap. If both inputs are null a null is returned. If either sketch is empty its Theta is ignored. If one is null the other is returned, which may be either Direct or heap-based if a cutback is required.

Parameters:

skA - The first ordered, CompactSketch argument.

skB - The second ordered, CompactSketch argument

k - The upper bound of the number of entries to be retained by the sketch

Returns:

the result as an ordered CompactSketch.