volumential.wranglers#

Expansion wranglers implementing the fpnd strategy.

fpnd means: the far field is handled by a particle approximation (a plain FMM over the quadrature nodes), while the near field is evaluated directly from precomputed interaction tables.

Two backends provide the far field:

volumential.wranglers.sumpy_backend – expansions generated by sumpy, works for every kernel sumpy can differentiate, and carries the Helmholtz near-field split.
volumential.wranglers.fmmlib_backend – expansions from pyfmmlib via boxtree.pyfmmlib_integration, restricted to 2D/3D Laplace and Helmholtz but considerably faster.

The remaining modules are the pieces both backends share: near-field table marshalling (table_data), the symmetry-orbit reconstruction used to keep reduced tables small (arithmetic_orbits, orbit_generated), and assorted device-array, kernel-introspection and layout-validation helpers.

volumential.expansion_wrangler_fpnd remains importable and re-exports every name this package defines.

Modules

`arithmetic_orbits`	Closed-form ('arithmetic') orbit reconstruction for reduced tables.
`barycentric`	Barycentric interpolation matrices and Gauss-Legendre nodes.
`box_layout`	Validation of the box/particle layout that table lookups assume.
`device_arrays`	Device-array plumbing shared by both wrangler backends.
`fmmlib_backend`	The pyfmmlib-based fpnd expansion wrangler.
`fmmlib_batched`	Batched far-field stages for the pyfmmlib backend.
`helmholtz_split`	Helmholtz near-field split correction for the sumpy backend.
`kernel_symmetry`	Introspection of `sumpy` kernels for near-field table symmetry.
`kernels`	Auxiliary `sumpy` expression kernels for the Helmholtz split.
`nearfield_cache`	Device-resident near-field table payload cache.
`orbit_generated`	Generated (search-derived) orbit reconstruction maps.
`orbit_lookup`	Open-addressed integer lookup tables for orbit reconstruction.
`split_terms`	Bookkeeping for Helmholtz-split term tables.
`sumpy_backend`	The sumpy-based fpnd expansion wrangler.
`table_data`	Marshalling of near-field interaction tables into device-ready arrays.
`timing`	Timing-future adapter for the boxtree FMM driver.