Fields And Scalars¶

Last changes: 23:47 29.08.2026Documentation changelog

Contract¶

This page records the current public Python authoring contract and canonical lowering; it does not redefine solver physics.

Governing equations¶

This API page introduces no independent governing equation. Physical equations belong to interaction and solver-lane pages.

Symbols and SI units¶

Every owned input has its SI unit below; \(1\) denotes dimensionless data.

Assumptions and validity¶

Constructor checks run immediately. Lowering and planning additionally check mesh cardinality, capability, and backend legality.

Python API¶

Python	Type	Default	SI unit	Validation	Meaning	Backend support	ProblemIR
`SaveField.field`	`str`	`required`	\(1\)	Canonical field ID. For example, `H_ex` requires `Exchange()`.	Canonical field ID. For example, `H_ex` requires `Exchange()`.	FEM/FDM CPU/GPU; planner checks combinations	`study.sampling.outputs[].field`
`SaveField.every`	`positive float or "auto"`	`required`	\(\mathrm{s}\)	Finite positive sampling period in seconds, or `"auto"`; step-count sampling is not accepted here.	Finite positive sampling period in seconds, or `"auto"`; step-count sampling is not accepted here.	FEM/FDM CPU/GPU; planner checks combinations	`study.sampling.outputs[].every`
`SaveScalar.scalar`	`str`	`required`	\(1\)	Canonical scalar ID. For example, `E_ex` requires `Exchange()`.	Canonical scalar ID. For example, `E_ex` requires `Exchange()`.	FEM/FDM CPU/GPU; planner checks combinations	`study.sampling.outputs[].scalar`
`SaveScalar.every`	`positive float or "auto"`	`required`	\(\mathrm{s}\)	Finite positive sampling period in seconds, or `"auto"`; step-count sampling is not accepted here.	Finite positive sampling period in seconds, or `"auto"`; step-count sampling is not accepted here.	FEM/FDM CPU/GPU; planner checks combinations	`study.sampling.outputs[].every`

Complete output stage scenario¶

Output requests are attached to the ordered stage, after the physical model and solver policy have been declared.

# %% Field and scalar output from a complete study
import fullmag as fm

nm = 1.0e-9
study = fm.study("output_api_example")
study.engine("fdm")
study.device("cpu", precision="double")
study.mode("strict")
study.objects.mesh.defaults(cell_size=(2 * nm, 2 * nm, 5 * nm))
study.exchange()
film = study.geometry(fm.Box(100 * nm, 20 * nm, 5 * nm), name="film")
film.Ms = 800.0e3
film.Aex = 13.0e-12
film.alpha = 0.02
film.m = fm.init.UniformMagnetization((1.0, 0.0, 0.0))
study.solver(integrator="rk45", fix_dt=1.0e-15, gamma=2.211e5)
study.stages.add_run(stage_id="run", until=1.0e-9).autosave(
    fm.StageAutosave(
        table=fm.TableAutosave(
            t_sampl=1.0e-12,
            quantities=["step", "e_ex", "e_total", "max_torque_T"],
        ),
        fields=[fm.FieldAutosave("H_ex", every=1.0e-12)],
    )
)

ProblemIR¶

The final column gives the serialized destination owned by the current lowering implementation.

Round-trip and failure semantics¶

Requested intent is preserved in Python and IR. Resolved execution is selected by the planner. Validation errors reject malformed values; unsupported combinations fail capability checks without silent fallback.

Discrete realization¶

This page owns authoring and lowering only; numerical realization belongs to solver-lane documentation.

Implementation mapping¶

The adjacent map anchors claims to packages/fullmag-py/src/fullmag/model/outputs.py and class SaveField.

Validation¶

Tests compare this inventory with live signatures and validate its source map.

Limitations¶

Representability does not prove every backend combination executable; planner capabilities are authoritative.

Scientific bibliography¶

No physical model is introduced. Primary references belong to consuming interaction pages.

Control Room crosswalk¶

Status: Table/field autosave and result inspection are partial; unsupported output formats remain not implemented.

Python/API surface	Control Room path	Status	Transaction
Parameters documented on this page	`Model Explorer -> Stages -> <stage> -> Autosave`	`partial`	Submit autosave draft; output resources are revised after execution
Parameters without a named UI field	`Model Explorer -> Stages -> <stage> -> Autosave`	`not implemented`	Python-only until implemented

frontend support is not implemented for output parameters not rendered by the autosave/result inspectors. See Control Room capability register for the support matrix and not implemented policy. Frontend source owner: apps/control-room/src/modules/inspector/panels/stages/AutosaveStageInspector.tsx (AutosaveStageInspector).

Source-code index¶

Claim	Path	Stable symbol	Responsibility	Evidence
SaveField constructor, validation, lowering	`packages/fullmag-py/src/fullmag/model/outputs.py`	`class SaveField`	Canonical Python API behavior	Ownership test and source-map validator