Package org.apache.datasketches.quantiles

Class DoublesSketchBuilder

java.lang.Object
org.apache.datasketches.quantiles.DoublesSketchBuilder
public class DoublesSketchBuilder extends Object
For building a new quantiles DoublesSketch.
Author:
Lee Rhodes

  • Constructor Summary

    Constructors
    Constructor
    Description
    DoublesSketchBuilder()
    Constructor for a new DoublesSketchBuilder.

  • Method Summary

    Modifier and Type
    Method
    Description
    UpdateDoublesSketch
    build()
    Returns an UpdateDoublesSketch with the current configuration of this Builder.
    UpdateDoublesSketch
    build(org.apache.datasketches.memory.WritableMemory dstMem)
    Returns a quantiles UpdateDoublesSketch with the current configuration of this builder and the specified backing destination Memory store.
    int
    getK()
    Gets the current configured k
    DoublesSketchBuilder
    setK(int k)
    Sets the parameter k that determines the accuracy and size of the sketch.
    String
    toString()
    Creates a human readable string that describes the current configuration of this builder.

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • DoublesSketchBuilder

      public DoublesSketchBuilder()
      Constructor for a new DoublesSketchBuilder. The default configuration is
      • k: 128. This produces a normalized rank error of about 1.7%
      • Memory: null

  • Method Details

    • setK

      public DoublesSketchBuilder setK(int k)
      Sets the parameter k that determines the accuracy and size of the sketch.
      Parameters:
      k - determines the accuracy and size of the sketch. It is recommended that k be a power of 2 to enable unioning of sketches with different k. It is only possible to union from larger k to smaller k.
      Returns:
      this builder

    • getK

      public int getK()
      Gets the current configured k
      Returns:
      the current configured k

    • build

      public UpdateDoublesSketch build()
      Returns an UpdateDoublesSketch with the current configuration of this Builder.
      Returns:
      a UpdateDoublesSketch

    • build

      public UpdateDoublesSketch build(org.apache.datasketches.memory.WritableMemory dstMem)
      Returns a quantiles UpdateDoublesSketch with the current configuration of this builder and the specified backing destination Memory store.
      Parameters:
      dstMem - destination memory for use by the sketch
      Returns:
      an UpdateDoublesSketch

    • toString

      public String toString()
      Creates a human readable string that describes the current configuration of this builder.
      Overrides:
      toString in class Object