Examples

Every script below ships in a source checkout under examples/. The order is the one in examples/README.md; each step teaches one decision a real design needs, and the last column says which port and boundary family the script actually builds, so you can find the one that matches your structure.

Steps 4 and 10 are the long ones — tens of minutes on CPU. The rest finish in seconds to a few minutes.

#	Script	What it teaches	Ports and boundaries
1	examples/quickstart/hello_world.py	install check, the minimal Simulation → run → probe loop	closed PEC box; soft point source and one probe; no port
2	examples/tutorials/boundary_spec_demo.py	choosing boundaries: CPML = open, PEC = closed (never mix roles), PMC symmetry, periodic cells	BoundarySpec per axis and per face — all four patterns; soft source and probe
3	examples/tutorials/slab_rt_flux_monitor.py	R(f)/T(f) the right way: add_flux_monitor plus a two-run reference subtraction, and why a probe FFT lies	CPML; TFSF plane wave; two flux monitors — flux monitors are not ports
4	examples/tutorials/nonuniform_patch_demo.py	graded z-mesh for a thin substrate, and verifying where the layers actually landed after smooth_grading shifts them	CPML; dz_profile graded mesh; soft source and probe
5	examples/tutorials/materials_and_dispersion.py	library and custom materials, why loss matters (the infinite-Q trap), Debye and Lorentz poles	CPML; soft source and probe; five small runs, one per material model
6	examples/tutorials/run_control_and_fields.py	n_steps vs num_periods vs until_decay, reading the truncation advisory, extracting field slices	CPML; soft source and probe
7	examples/tutorials/ports_and_sparams_101.py	which port suits which structure, S11 basics, and the standing-wave-null bins the extractor marks unreliable	the script’s five-entry port decision tree — add_msl_port, add_waveguide_port, add_coaxial_port, lumped add_port, add_lumped_rlc; CPML and PEC
8	examples/tutorials/resonance_harminv.py	ring-down resonance extraction, picking a mode by physics rather than amplitude, record length vs frequency resolution	closed PEC cavity via BoundarySpec; soft source and probe; no port (a port would load the cavity)
9	examples/tutorials/antenna_farfield_pattern.py	near-to-far-field boxes done right — every face at least half the shortest monitored wavelength from the radiator — and directivity against the textbook short dipole	CPML; add_ntff_box; soft source
10	examples/tutorials/patch_antenna_demo.py	a real antenna end to end: a stack registered to the built mesh, identifying the radiating mode from the far field rather than by amplitude rank, a settling witness, and an error budget against openEMS	CPML; graded dz_profile; add_ntff_box; soft source and probe
11	examples/tutorials/rcs_scattering.py	radar cross-section with subtract_incident_reference=True, and why deep nulls near the collection box carry larger error	CPML; TFSF illumination with an empty reference run
12	examples/inverse_design/differentiable_s11_design.py	the differentiable design loop: jax.grad end to end through the public compute_waveguide_s_matrix API, cross-checked against central finite differences	CPML; two WR-90 add_waveguide_port above cutoff; differentiates on normalize=False
13	examples/tutorials/artifact_report_demo.py	exporting a shareable scene, mesh/preflight metadata, Markdown report and manifest	PEC box; lumped add_port and a probe; exports without running FDTD

Script	What it is	Ports and boundaries
examples/tutorials/adi_solver_demo.py	the ADI solver’s timestep-vs-accuracy trade, read three ways against an exact cavity oracle — see ADI Solver	closed PEC cavity via BoundarySpec; soft source and probe
examples/tutorials/cad_mesh_import_demo.py	importing an STL part with MeshShape and an explicit mm→m scale; needs the optional rfx-fdtd[cad] extra and exits cleanly without it	CPML; soft source
examples/inverse_design/multilayer_ar_coating.py	a 3-layer AR coating optimized with jax.value_and_grad through forward(eps_override=...), cross-checked against an analytic transfer-matrix optimum	CPML on x, periodic y and z (1D-equivalent); soft source and two probes
examples/inverse_design/field_observable_shielding.py	pooling two add_dft_plane_probe planes into one worst-case-leakage scalar with field_softmax, then descending on it	CPML; TFSF plane wave; two DFT plane probes behind the stack
examples/inverse_design/progressive_demo.py	how progressive_optimize runs a design at increasing mesh resolutions, upsampling the latent between stages. Its own docstring calls it a minimal API demonstration with a trivial optimum, not a cross-validation	CPML on all sides; soft source and probe
examples/config/microstrip_thru.yaml	the declarative YAML front-end for the same Simulation API, driven by rfx run / rfx plot / rfx export-geometry	CPML; two 50 Ω lumped wire ports, port 1 excited and port 2 a passive matched load

Read the preflight output every time. Its warnings identify conditions that can invalidate a result — lossless-dielectric Q traps, graded-mesh rasterization errors, incomplete ring-down.

The scripts under validation/crossval/ check the solver against an analytic result or another solver. (examples/crossval/ in a checkout is a tombstone README from the 2026-07 restructure; the scripts moved.) They assume the structure is already understood and gate on numbers, so they teach nothing about setup, and a passing run supports only its own committed geometry, mesh, band, source, port and observable. Benchmarks lists every case with its pass criteria and reproduce command; Cross-Solver Validation explains what the exit codes mean.