Package de.jungblut.sketching

Class CountMinSketch<T>

  • public class CountMinSketch<T>
extends java.lang.Object

    • Constructor Summary

      Constructors 
      Constructor Description
      CountMinSketch​(int tableWidth, int tableHeight, com.google.common.hash.Funnel<T> funnel)
      Creates a new CountMinSketch.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void add​(T obj)
      Adds this object to the min sketch.
      int approximateCount​(T obj)
      Gives an approximate count of how often this element was seen through add(Object).

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • CountMinSketch

        public CountMinSketch​(int tableWidth,
                      int tableHeight,
                      com.google.common.hash.Funnel<T> funnel)
        Creates a new CountMinSketch. This will allocate a 2D array of (tableHeight * tableWidth) integers, which is the whole memory constraint of the counting sketch. The height of the table tells how many hash functions to use.
        Parameters:
        tableWidth - the width of the counter table.
        tableHeight - the height of the counter table (as in how many hashing functions to use).
        funnel - the funnel to hash an object.

    • Method Detail

      • add

        public void add​(T obj)
        Adds this object to the min sketch.

      • approximateCount

        public int approximateCount​(T obj)
        Gives an approximate count of how often this element was seen through add(Object).
        Returns:
        0 if it was never seen, an approximate count otherwise.