Calculating the similarity of two lists

Question

I have two lists:

eg. a = [1,8,3,9,4,9,3,8,1,2,3] and b = [1,8,1,3,9,4,9,3,8,1,2,3]

Both contain ints. There is no meaning behind the ints (eg. 1 is not \'cl

Answer 1

It sounds like edit (or Levenshtein) distance is precisely the right tool for the job.

Here is one Python implementation that can be used on lists of integers: http://hetland.org/coding/python/levenshtein.py

Using that code, levenshtein([1,8,3,9,4,9,3,8,1,2,3], [1,8,1,3,9,4,9,3,8,1,2,3]) returns 1, which is the edit distance.

Given the edit distance and the lengths of the two arrays, computing a "percentage similarity" metric should be pretty trivial.