Package org.apache.datasketches.cpc

Class CpcWrapper

  • public final class CpcWrapper
extends Object
    This provides a read-only view of a serialized image of a CpcSketch, which can be on-heap or off-heap represented as a Memory object, or on-heap represented as a byte array.
    Author:
    Lee Rhodes, Kevin Lang

    • Constructor Summary

      Constructors 
      Constructor Description
      CpcWrapper​(byte[] byteArray)
      Construct a read-only view of the given byte array that contains a CpcSketch.
      CpcWrapper​(org.apache.datasketches.memory.Memory mem)
      Construct a read-only view of the given Memory that contains a CpcSketch

    • Constructor Detail

      • CpcWrapper

        public CpcWrapper​(org.apache.datasketches.memory.Memory mem)
        Construct a read-only view of the given Memory that contains a CpcSketch
        Parameters:
        mem - the given Memory

      • CpcWrapper

        public CpcWrapper​(byte[] byteArray)
        Construct a read-only view of the given byte array that contains a CpcSketch.
        Parameters:
        byteArray - the given byte array

    • Method Detail

      • getEstimate

        public double getEstimate()
        Returns the best estimate of the cardinality of the sketch.
        Returns:
        the best estimate of the cardinality of the sketch.

      • getFamily

        public static Family getFamily()
        Return the DataSketches identifier for this CPC family of sketches.
        Returns:
        the DataSketches identifier for this CPC family of sketches.

      • getLgK

        public int getLgK()
        Returns the configured Log_base2 of K of this sketch.
        Returns:
        the configured Log_base2 of K of this sketch.

      • getLowerBound

        public double getLowerBound​(int kappa)
        Returns the best estimate of the lower bound of the confidence interval given kappa, the number of standard deviations from the mean.
        Parameters:
        kappa - the given number of standard deviations from the mean: 1, 2 or 3.
        Returns:
        the best estimate of the lower bound of the confidence interval given kappa.

      • getUpperBound

        public double getUpperBound​(int kappa)
        Returns the best estimate of the upper bound of the confidence interval given kappa, the number of standard deviations from the mean.
        Parameters:
        kappa - the given number of standard deviations from the mean: 1, 2 or 3.
        Returns:
        the best estimate of the upper bound of the confidence interval given kappa.