function [attSimilarity] = CalcOneAttributeSimilarity(data, attributes, attId, returnSparse)
    n = size(data,1);
    attSimilarity = zeros(n,n);
    
    %Note - Sigal, replace 0 and 2 so we can have sparse matrix
    
    for i=1:n
        for j=1:i-1
            val_i = attributes(i,attId);
            val_j = attributes(j,attId);
            if val_i == 0 && val_j == 0
                attSimilarity(i,j) = 2;
            elseif val_i == val_j
                attSimilarity(i,j) = 1;
%             else    % can be skipped as already initilaize with zero
%                 attSimilarity(i,j) = 0;
            end
            attSimilarity(j,i) = attSimilarity(i,j);
        end
    end

    for i = 1 : size(attSimilarity,1)
        attSimilarity(i,i) = 1;
    end

    if returnSparse == 1
        attSimilarity = sparse(attSimilarity);
    end

end %function