fn origin_waves(
modes: impl Iterator<Item = Mode>,
ks: [Complex; 2],
radial: Radial,
) -> Result<WaveSet>Expand description
Spherical helicity waves of modes about the origin with wavenumbers ks. Only
the wavenumbers of helicities with modes are evaluated. The other may be zero,
which WaveSet::new rejects, so it takes the evaluated one’s value.