Class LevenshteinDetailedDistance

All Implemented Interfaces:
EditDistance<LevenshteinResults>, SimilarityScore<LevenshteinResults>

An algorithm for measuring the difference between two character sequences.

This is the number of changes needed to change one sequence into another, where each change is a single character modification (deletion, insertion or substitution).

  • Constructor Details

    • LevenshteinDetailedDistance

      This returns the default instance that uses a version of the algorithm that does not use a threshold parameter.

      See Also:
    • LevenshteinDetailedDistance

      If the threshold is not null, distance calculations will be limited to a maximum length.

      If the threshold is null, the unlimited version of the algorithm will be used.

      threshold - If this is null then distances calculations will not be limited. This may not be negative.
  • Method Details

    • getDefaultInstance

      Gets the default instance.
      The default instace
    • apply

      Finds the Levenshtein distance between two Strings.

      A higher score indicates a greater distance.

      The previous implementation of the Levenshtein distance algorithm was from

      Chas Emerick has written an implementation in Java, which avoids an OutOfMemoryError which can occur when my Java implementation is used with very large strings.
      This implementation of the Levenshtein distance algorithm is from

       distance.apply(null, *)             = IllegalArgumentException
       distance.apply(*, null)             = IllegalArgumentException
       distance.apply("","")               = 0
       distance.apply("","a")              = 1
       distance.apply("aaapppp", "")       = 7
       distance.apply("frog", "fog")       = 1
       distance.apply("fly", "ant")        = 3
       distance.apply("elephant", "hippo") = 7
       distance.apply("hippo", "elephant") = 7
       distance.apply("hippo", "zzzzzzzz") = 8
       distance.apply("hello", "hallo")    = 1
      Specified by:
      apply in interface EditDistance<LevenshteinResults>
      Specified by:
      apply in interface SimilarityScore<LevenshteinResults>
      left - the first string, must not be null
      right - the second string, must not be null
      result distance, or -1
      IllegalArgumentException - if either String input null
    • getThreshold

      Gets the distance threshold.
      The distance threshold