Python

Python API Reference

March 14, 2026

Api, Reference, Python

Field Classes#

All field classes follow the same interface:

compute(magnetization) – returns the effective field as an (n, 3) array
energy(magnetization) – returns the energy as a scalar (Joules)

Magnetization m is always an (n, 3) array of unit vectors.

DemagFieldFK#

Demagnetizing field via the Fredkin-Koehler scalar potential method. This is the primary solver and supports multiple BEM backends.

DemagFieldFK(coordinates, elements, Ms, *,
           scale=1.0, tolerance=1e-8,
           solver=SolverType.AMG_CG,
           h2_cache="", h2params=None,
           fmm_params=None, backend=None,
           tree_type=None)

Parameter	Type	Description
`coordinates`	`(n, 3)`	Node positions
`elements`	`(ntet, 4)`	Tetrahedral connectivity, 0-indexed
`Ms`	`(n,)`	Saturation magnetization per node (A/m)
`scale`	`float`	Length unit: `1.0` = m, `1e-9` = nm
`tolerance`	`float`	Iterative solver tolerance
`solver`	`SolverType`	GPU solver preset
`h2_cache`	`str`	H2 matrix cache file path (empty = no caching)
`h2params`	`ParamsFKH2Lib`	H2-matrix compression parameters
`fmm_params`	`ParamsFKFMM`	GPU FMM parameters
`backend`	`BemBackend`	BEM backend (default: `FMM_GPU`)
`tree_type`	`TreeType` or `str`	FMM tree strategy

Additional methods: