Results and Observables

Result is the object returned by Simulation.run().

Primary fields

Field	Meaning	Public use
`state`	solver state / checkpoint payload	restart and debugging
`time_series`	recorded probe values over time	ringdown, transient response, Harminv
`s_params`	lumped/wire port S-matrix	matching, filters, de-embedding
`freqs`	frequency axis for frequency-domain outputs	pair with S-parameter and DFT outputs
`ntff_data`	near-to-far-field accumulation	radiation patterns where documented
`dft_planes`	frequency-domain plane observables	slices and field maps
`flux_monitors`	plane flux accumulations	transmission / reflection analysis
`waveguide_sparams`	per-port waveguide diagnostics	waveguide workflows
`snapshots`	saved field snapshots	visualization and post-processing
`grid`	mesh metadata	reproducibility checks
`dt`	timestep	time-axis conversion

S-parameter result schemas

Calculator	Result object	Public status
`run(compute_s_params=True)` with lumped/wire `add_port(...)`	`Result.s_params`, `Result.freqs`	documented path for the matching port family
`forward(port_s11_freqs=...)` with lumped/wire `add_port(...)`	`ForwardResult.s_params`, `ForwardResult.freqs`	differentiable S11 vectors, not a full multi-port matrix
`compute_msl_s_matrix(...)`	`MSLSMatrixResult`	specialized microstrip-line workflow
`compute_waveguide_s_matrix(...)`	`WaveguideSMatrixResult`	rectangular waveguide workflow
`compute_coaxial_line_reflection(...)`	`CoaxialLineReflectionResult`	one-port coaxial transmission-line reflection envelope
`run(...)` with a single waveguide port	`Result.waveguide_sparams[name]`	diagnostic per-port output

Sources, TFSF, probes, DFT planes, and flux monitors do not automatically define a high-level S-matrix workflow. Coaxial reports should use the documented line-reflection method.

Observable builders that feed `Result`

Builder	Result field	Typical use
`add_probe(...)` / `add_vector_probe(...)`	`time_series`	transient response, ringdown, local field traces
`add_dft_plane_probe(...)`	`dft_planes`	frequency-domain field slices
`add_flux_monitor(...)`	`flux_monitors`	reflection / transmission bookkeeping
`add_ntff_box(...)`	`ntff_data`, `ntff_box`	far-field accumulation

Finite-size flux monitors use the same per-cell Poynting integrand as full-plane monitors. When both are summed over the same index window, they agree to machine precision; differences from size=None full-plane monitors are coverage choices, not a separate stability model.

Resonance extraction

Result.find_resonances() runs Harminv-style mode extraction on a probe time series.

result = sim.run(n_steps=8000)
modes = result.find_resonances(freq_range=(1.5e9, 3.5e9))

Use this on a clean probe signal when you want a resonance estimate that is less dependent on port calibration than S-parameters.

Port-observable helpers

rfx.validation provides helper functions for checking S-matrix-like arrays for shape, finite values, frequency metadata, port names, and caller-selected passivity / reciprocity limits.

from rfx import validate_port_smatrix, assert_port_smatrix_valid

report = validate_port_smatrix(result, check_passivity=True, passivity_tol=0.02)
print(report.summary())

These helpers are useful for regression checks. They do not turn an undocumented workflow into the recommended default path.

Validated observables

For public docs, describe observables in simple terms:

time_series and Harminv are the recommended resonance path.
lumped/wire, MSL, waveguide, and coaxial-line S-parameter/reflection workflows each have their own calculator and envelope.
NTFF/far-field outputs should be used where the relevant guide documents the workflow.
Other fields are useful analysis surfaces; use them with the documented support status for the workflow.