Possibly a faster way to compute NODF?

nodf_script

M = 3; N = 4;
p = .2;

B = double(rand(M,N)>p);

C1 = B*B';
D1 = repmat(diag(C1),1,M);
eta1 = C1.*(D1~=D1')./(min(D1,D1'));

C2 = B'*B;
D2 = repmat(diag(C2),1,N);
eta2 = C2.*(D2~=D2')./(min(D2,D2'));

nu = sum(eta1(:))+sum(eta2(:));