% array of struct containing the iriscode of the 20 persons
person = repmat(struct('iriscode', []), 20, 1);

% loading files
for i=1:20
    filename = sprintf('lab_week2_data/person%02d.mat', i);
    person(i) = load(filename);
end

S = zeros(1, 1000);
for i=1:1000
    % random person
    random_iriscode = person(randi(20)).iriscode;
    % random permutation of rows to be sure that we don't pick the same row
    iriscode_perm = randperm(20);
    % the first two rows with the iriscode
    row1 = random_iriscode(iriscode_perm(1), :);
    row2 = random_iriscode(iriscode_perm(2), :);
    xor1 = xor(row1, row2);
    % normalized hamming distance
    %S(i) = sum(xor(row1, row2) == 1) / 30;
end