[2] Rapp, R.H.; A Fortran Program for the Computation of Gravimetric Quantities from High Degree Spherical Harmonic Expansions, Ohio State University Columbus; report; 1982;
[2] Rapp, R.H.; A Fortran Program for the Computation of Gravimetric Quantities from High Degree Spherical Harmonic Expansions, Ohio State University Columbus; report; 1982;
needed for the computation of the vector spherical harmonics. The resulting tensor has shape
(2, mmax, lmax, len(t)).
computation follows
Parameters
-----------
mmax: int
Maximum order of the spherical harmonics
lmax: int
Maximum degree of the spherical harmonics
t: torch.Tensor
Tensor of positions at which to evaluate the Legendre polynomials
norm: Optional[str]
Normalization of the Legendre polynomials
inverse: Optional[bool]
Whether to compute the inverse Legendre polynomials
csphase: Optional[bool]
Whether to apply the Condon-Shortley phase (-1)^m
Returns
-------
out: torch.Tensor
Tensor of Legendre polynomial values
References
----------
[2] Wang, B., Wang, L., Xie, Z.; Accurate calculation of spherical and vector spherical harmonic expansions via spectral element grids; Adv Comput Math.