Package org.apache.commons.text.similarity

Class HammingDistance

java.lang.Object
org.apache.commons.text.similarity.HammingDistance
All Implemented Interfaces:
EditDistance<Integer>, SimilarityScore<Integer>
public class HammingDistance
extends Object
implements EditDistance<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 http://en.wikipedia.org/wiki/Hamming_distance.

Since:
1.0

  • Constructor Details

  • Method Details

    • apply

      public Integer apply​(CharSequence left, CharSequence right)
      Find 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 EditDistance<Integer>
      Specified by:
      apply in interface SimilarityScore<Integer>
      Parameters:
      left - the first CharSequence, must not be null
      right - the second CharSequence, must not be null
      Returns:
      distance
      Throws:
      IllegalArgumentException - if either input is null or if they do not have the same length