void dRz_dtheta(Matrix3x3 &out, double theta)
{
out.setZero();
double s = sin(theta);
double c = cos(theta);
out(0,0) = -s; out(0,1) = -c;
out(1,0) = c; out(1,1) = -s;
}
Matrix3x3 SHVector::mu2() const {
const Float sqrt5o3 = std::sqrt((Float) 5/ (Float) 3);
const Float sqrto3 = std::sqrt((Float) 1/ (Float) 3);
Matrix3x3 result;
result.setZero();
SAssert(m_bands > 0);
result(0, 0) = result(1, 1) =
result(2, 2) = sqrt5o3*operator()(0,0);
if (m_bands >= 3) {
result(0, 0) += -operator()(2,0)*sqrto3 + operator()(2,2);
result(0, 1) = operator()(2,-2);
result(0, 2) = -operator()(2, 1);
result(1, 0) = operator()(2,-2);
result(1, 1) += -operator()(2,0)*sqrto3 - operator()(2,2);
result(1, 2) = -operator()(2,-1);
result(2, 0) = -operator()(2, 1);
result(2, 1) = -operator()(2,-1);
result(2, 2) += 2*sqrto3*operator()(2,0);
}
return result * (2*std::sqrt((Float) M_PI / 15));
}
