function res = getspecmatr(num)
    vecs = getvecs (num, 16, 7);
    x1i  = inv(vecs(1:7, :));
    if (x1i == floor(x1i))
        x2   = vecs(2:8, :);
        res = transpose (mod (x1i * x2, 2));
    else
        res = [0, 0];
    endif
endfunction
