58 double eta = other.
getE();
61 alpha = (1.0 - eta * eta / 3.0);
66 beta = (1.0 - delta * delta - alpha) / (eta * eta);
69 result(0, 0) = alpha + other.
getE1() * other.
getE1() * beta;
70 result(1, 1) = alpha + other.
getE2() * other.
getE2() * beta;
71 result(1, 0) = result(0, 1) = other.
getE1() * other.
getE2() * beta;