Module expansion 

Cylindrical expansion matrices between bases and over periodic arrays, with analytic pullbacks. Entries that share a CouplingKey share one coefficient, evaluated once.

Upstream: the treams.Expand and treams.ExpandLattice operators between cylindrical bases.

Modules

lattice_state 🔒

Saved periodic geometry and coupling labels; restoring performs no Ewald sum. treams-rs extension.

Structs

CouplingKey 🔒

The key of one distinct coupling coefficient. A coefficient depends on its mode pair only through these fields.

Couplings 🔒

The distinct coefficients of a cylindrical coupling matrix and the entries they fill. A coefficient depends on the mode pair only through its key, and entries of different axial wavenumbers or polarizations vanish.

ExpansionResidual

What expansion saves for its pullback: the bases, the wavenumbers, the radial kind and the distinct couplings.

LatticeExpansionResidual

What lattice_expansion saves for its pullback: the bases, the wavenumbers, the lattice, the split and the distinct couplings.

Constants

PARALLEL 🔒

Expansion coefficients and their jets evaluate in parallel from this many distinct couplings.

Functions

axial_groups 🔒

The sorted distinct axial wavenumbers of both bases: the entries of the axial cotangent of pullback_axial.

expansion

Construct a cylindrical expansion matrix in the supplied mode order.

for_each_coupled 🔒

Call f(row, column) for each coupled entry of a destination and a source basis, column by column: equal axial wavenumbers and polarizations.

lattice_expansion

Periodic cylindrical coupling with exact axial/polarization selection and cached orders.