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stringmatlabhamming-distancevariable-length

Calculate Hamming distance between strings of variable length in Matlab

I would like to calculate the Hamming distance between two strings of variable length in Matlab. For fixed length strings the following syntax solves my problem:

str1 = 'abcde';
str2 = 'abedc';

sum(str1 ~= str2)

ans = 2

How can I do this efficiently for variable length strings?

Thank you!

EDIT: Because this is a legitimate question: For every character one string is longer then the other, the Hamming distance should be incremented. So for example for

str1 = 'abcdef';
str2 = 'abc';

The answer should be 3.

Solution

  • Here's a way to do it:

    str1 = 'abcdef';
str2 = 'abc';
clear t
t(1,:) = str1+1; % +1 to make sure there are no zeros
t(2,1:numel(str2)) = str2+1; % if needed, this right-pads with zero or causes t to grow
result = sum(t(1,:)~=t(2,:));