Comparing two different strings

Hello, this is my first post so please go easy on me.

I want to compare two strings which I obtained from an OCR, but I need to do it letter by letter. The catch is that one string may have some missing letters or some unwanted characters compared to the other.

My first idea was to use strsplit to separate the two strings in words, but after that I've no clue what to do next.

Thanks a lot!

Answer 1

[Image Analyst]

See Loren's blog on "edit distance": https://blogs.mathworks.com/loren/2015/10/14/40-year-old-algorithm-that-cannot-be-improved/?s_tid=answers_rc2-3_p6_MLT

and Cleve's blog: https://blogs.mathworks.com/cleve/2017/08/14/levenshtein-edit-distance-between-strings/?s_tid=answers_rc2-2_p5_MLT

Answer 2

[Stephen23]

You could use the edit distance as a measure of similarity:

 >> C = {'live','eve','believe','belive'};
 >> cellfun(@(c)wfEdits(c,'beleive'),C)
 ans =
     3     4     2     1

Thus showing that 'belive' is the closest to 'beleive'. The function is:

function d = wfEdits(S1,S2)
% Wagner–Fischer algorithm to calculate the edit distance / Levenshtein distance.
%
N1 = 1+numel(S1);
N2 = 1+numel(S2);
%
D = zeros(N1,N2);
D(:,1) = 0:N1-1;
D(1,:) = 0:N2-1;
%
for r = 2:N1
  for c = 2:N2
    D(r,c) = min([D(r-1,c)+1, D(r,c-1)+1, D(r-1,c-1)+~strcmpi(S1(r-1),S2(c-1))]);
  end
end
d = D(end);
%
end