locateindex( M, m)

function i = locateindex( M, m)
%ISELEMENTUNIQUE checks if matrix is unique defined by tuple of 4 elements
%in
%   M: n*4 matrix to comapre against 
%   m: 1*4 matrix to compare 
%out
%   i: index where it's found.  0 if not found

[numtuples, temp] = size(M);

for r=1:numtuples
    am = M(r,:);
    if all(am == m)
        i = r;
        return;
    end
end
i = 0;