pub fn expansion(
destination: Basis,
source: Basis,
ks: [Complex; 2],
helicity: bool,
radial: Radial,
) -> Result<(DMatrix<Complex>, ExpansionResidual)>Expand description
Construct a regular or singular spherical expansion matrix, which maps source coefficients to destination coefficients.
Upstream: the treams.Expand operator (treams.operators.expand) between spherical
bases.