mode_sign_convention

When comparing against different cases, it is important that the modes share a common sign convention.

In this case, modes will be arranged such that the z-coordinate of the first free end is positive.

If the z-coordinate is 0, then the y-coordinate is forced to be positive, then x, followed by the CRV in y, x and z.

returns

Eigenvectors following the aforementioned sign convention.

rtype

np.ndarray