Package org.apache.datasketches.tuple

Class Union<S extends Summary>

java.lang.Object
org.apache.datasketches.tuple.Union<S>
Type Parameters:
S - Type of Summary
public class Union<S extends Summary>
extends Object
Compute the union of two or more generic tuple sketches or generic tuple sketches combined with theta sketches. A new instance represents an empty set.

  • Constructor Summary

    Constructors 
    Constructor Description
    Union​(int nomEntries, SummarySetOperations<S> summarySetOps)
    Creates new Union instance with instructions on how to process two summaries that overlap.
    Union​(SummarySetOperations<S> summarySetOps)
    Creates new Union instance with instructions on how to process two summaries that overlap.

  • Method Summary

    Modifier and Type Method Description
    CompactSketch<S> getResult()
    Gets the result of a sequence of stateful union operations as an unordered CompactSketch
    void reset()
    Resets the internal set to the initial state, which represents an empty set.
    void union​(Sketch thetaSketch, S summary)
    Performs a stateful union of the internal set with the given thetaSketch by combining entries using the hashes from the theta sketch and summary values from the given summary and rules from the summarySetOps defined by the Union constructor.
    void union​(Sketch<S> tupleSketch)
    Performs a stateful union of the internal set with the given tupleSketch.
    CompactSketch<S> union​(Sketch<S> tupleSketch, Sketch thetaSketch, S summary)
    Perform a stateless, pair-wise union operation between a tupleSketch and a thetaSketch.
    CompactSketch<S> union​(Sketch<S> tupleSketchA, Sketch<S> tupleSketchB)
    Perform a stateless, pair-wise union operation between two tuple sketches.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • Union

      public Union​(SummarySetOperations<S> summarySetOps)
      Creates new Union instance with instructions on how to process two summaries that overlap. This will have the default nominal entries (K).
      Parameters:
      summarySetOps - instance of SummarySetOperations

    • Union

      public Union​(int nomEntries, SummarySetOperations<S> summarySetOps)
      Creates new Union instance with instructions on how to process two summaries that overlap.
      Parameters:
      nomEntries - nominal entries (K). Forced to the nearest power of 2 greater than given value.
      summarySetOps - instance of SummarySetOperations

  • Method Details

    • union

      public CompactSketch<S> union​(Sketch<S> tupleSketchA, Sketch<S> tupleSketchB)
      Perform a stateless, pair-wise union operation between two tuple sketches. The returned sketch will be cutback to the smaller of the two k values if required.

      Nulls and empty sketches are ignored.

      Parameters:
      tupleSketchA - The first argument
      tupleSketchB - The second argument
      Returns:
      the result ordered CompactSketch on the heap.

    • union

      public CompactSketch<S> union​(Sketch<S> tupleSketch, Sketch thetaSketch, S summary)
      Perform a stateless, pair-wise union operation between a tupleSketch and a thetaSketch. The returned sketch will be cutback to the smaller of the two k values if required.

      Nulls and empty sketches are ignored.

      Parameters:
      tupleSketch - The first argument
      thetaSketch - The second argument
      summary - the given proxy summary for the theta sketch, which doesn't have one. This may not be null.
      Returns:
      the result ordered CompactSketch on the heap.

    • union

      public void union​(Sketch<S> tupleSketch)
      Performs a stateful union of the internal set with the given tupleSketch.
      Parameters:
      tupleSketch - input tuple sketch to merge with the internal set.

      Nulls and empty sketches are ignored.

    • union

      public void union​(Sketch thetaSketch, S summary)
      Performs a stateful union of the internal set with the given thetaSketch by combining entries using the hashes from the theta sketch and summary values from the given summary and rules from the summarySetOps defined by the Union constructor.
      Parameters:
      thetaSketch - the given theta sketch input. If null or empty, it is ignored.
      summary - the given proxy summary for the theta sketch, which doesn't have one. This may not be null.

    • getResult

      public CompactSketch<S> getResult()
      Gets the result of a sequence of stateful union operations as an unordered CompactSketch
      Returns:
      result of the stateful unions so far

    • reset

      public void reset()
      Resets the internal set to the initial state, which represents an empty set. This is only useful after sequences of stateful union operations.