Package org.apache.commons.text.similarity

Class HammingDistance

  • All Implemented Interfaces:
    java.util.function.BiFunction<java.lang.CharSequence,​java.lang.CharSequence,​java.lang.Integer>, EditDistance<java.lang.Integer>, ObjectSimilarityScore<java.lang.CharSequence,​java.lang.Integer>, SimilarityScore<java.lang.Integer>
    public class HammingDistance
extends java.lang.Object
implements EditDistance<java.lang.Integer>
    The hamming distance between two strings of equal length is the number of positions at which the corresponding symbols are different.

    For further explanation about the Hamming Distance, take a look at its Wikipedia page at https://en.wikipedia.org/wiki/Hamming_distance.

    Since:
    1.0

    • Constructor Summary

      Constructors 
      Constructor Description
      HammingDistance()
      Creates a new instance.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.Integer apply​(java.lang.CharSequence left, java.lang.CharSequence right)
      Computes the Hamming Distance between two strings with the same length.
      <E> java.lang.Integer apply​(SimilarityInput<E> left, SimilarityInput<E> right)
      Computes the Hamming Distance between two strings with the same length.

      • Methods inherited from class java.lang.Object

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

      • Methods inherited from interface java.util.function.BiFunction

        andThen

    • Constructor Detail

    • Method Detail

      • apply

        public java.lang.Integer apply​(java.lang.CharSequence left,
                               java.lang.CharSequence right)
        Computes the Hamming Distance between two strings with the same length.

        The distance starts with zero, and for each occurrence of a different character in either String, it increments the distance by 1, and finally return its value.

        Since the Hamming Distance can only be calculated between strings of equal length, input of different lengths will throw IllegalArgumentException 

         distance.apply("", "")               = 0
 distance.apply("pappa", "pappa")     = 0
 distance.apply("1011101", "1011111") = 1
 distance.apply("ATCG", "ACCC")       = 2
 distance.apply("karolin", "kerstin"  = 3
        Specified by:
        apply in interface java.util.function.BiFunction<java.lang.CharSequence,​java.lang.CharSequence,​java.lang.Integer>
        Specified by:
        apply in interface ObjectSimilarityScore<java.lang.CharSequence,​java.lang.Integer>
        Specified by:
        apply in interface SimilarityScore<java.lang.Integer>
        Parameters:
        left - the first input, must not be null.
        right - the second input, must not be null.
        Returns:
        distance.
        Throws:
        java.lang.IllegalArgumentException - if either input is null or if they do not have the same length.

      • apply

        public <E> java.lang.Integer apply​(SimilarityInput<E> left,
                                   SimilarityInput<E> right)
        Computes the Hamming Distance between two strings with the same length.

        The distance starts with zero, and for each occurrence of a different character in either String, it increments the distance by 1, and finally return its value.

        Since the Hamming Distance can only be calculated between strings of equal length, input of different lengths will throw IllegalArgumentException 

         distance.apply("", "")               = 0
 distance.apply("pappa", "pappa")     = 0
 distance.apply("1011101", "1011111") = 1
 distance.apply("ATCG", "ACCC")       = 2
 distance.apply("karolin", "kerstin"  = 3
        Type Parameters:
        E - The type of similarity score unit.
        Parameters:
        left - the first input, must not be null.
        right - the second input, must not be null.
        Returns:
        distance.
        Throws:
        java.lang.IllegalArgumentException - if either input is null or if they do not have the same length.
        Since:
        1.13.0