Give a wing's mesh and airfoil settings a home in the settings file

[1-Bart-1]

obj_to_yaml, the section solvers, the shrink wrap and the live polars all take
arguments that no settings file held. Every caller restated them, and a caller
that gathered them into a struct of its own could only forward them one by one.

A wing now carries two optional blocks:

wings:
  - name: SK100
    obj_file: obj/SK100SA_3d.obj
    crease_frac: 0.75
    mesh:                       # how the .obj is sliced into sections
      n_sections: 45
      n_bins: 200
      rotation: [[0, 0, -1], [-1, 0, 0], [0, 1, 0]]
      wingtip_distance: 0.05
      clearance: 0.0
      min_concave_radius: 0.2
    airfoil:                    # what those sections are solved with
      solver: neuralfoil        # neuralfoil | xfoil
      model_size: large
      n_crit: 4.0
      xtr_upper: 0.05
      xtr_lower: 0.05
      alpha_range: [-15, 3, 90]
      delta_range: [-40, 10, 40]
      v_app: 25.0
      chord_ref: 6.0
      table_format: arrow

Both default, so every existing vsm_settings.yaml loads unchanged — this is
additive.

What falls out of it

The backend becomes a setting. solver: xfoil runs a whole dataset through the
viscous panel code. It used to be whichever solver a script had written into its
obj_to_yaml call.

The live polars stop inventing their own settings. LivePolarSettings
duplicated model_size and n_crit with nothing able to fill them, so a wing
tabulated at n_crit = 4 on the large network was re-solving in flight at 9
on xlarge. Different transition criticality, different network, same wing — and
nothing said so. LivePolarSettings(airfoil) now reads the block the tables came
from.

Reynolds is stated once. reynolds(set, wing) takes the air from
solver_settings, which already held density and mu, and the reference speed
and chord from airfoil:. Callers were carrying a second copy of rho/mu.

API

MeshSettings, AirfoilSettings, and airfoil_solver, alpha_range,
delta_range, reynolds, rotation_matrix, slice_args, preview_args.
NeuralFoilSolver, XFoilSolver, ShrinkWrap and LivePolarSettings each gain a
constructor taking the block that configures them, so slice_args(wing) splats
straight into obj_to_yaml or plot_slices_3d and the picture and the dataset
cannot disagree.

Tests

test/settings/test_settings.jl: both blocks parsed off a YAML string, the
rotation matrix, the two ranges, Reynolds against its definition, the solver
selection, the live settings matching the table settings, the slice_args and
preview_args shapes, and rejection of an unknown solver or table format. Plus
the existing dual-wing file asserting the defaults still apply when neither block
is named. 21 passing.

🤖 Generated with Claude Code

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Codecov Report

✅ All modified and coverable lines are covered by tests.

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[1-Bart-1]

@1-Bort-1 please fix the failing tests on windows.

[1-Bart-1]

@1-Bort-1 whoah this is a big change, making the test a lot less strict. It should be investigated a lot better if there is a different issue causing the relative error to be so high. And based on the solver tolerance, what would be the maximum relative error we can expect?

[1-Bart-1]

@1-Bort-1 the explanation about not being able to drift is not necessary in this docstring.

[1-Bart-1]

@1-Bort-1 The changelog should be bulletpoint style like the rest of the changelog

[1-Bort-1]

_{Superseded by the review further down this thread.}

[1-Bort-1]

MAJOR: obj_to_yaml has no n_bins parameter at all (obj_to_yaml.jl:187-196 never forwards one, so the dataset always marches at perpendicular_sections' default 60): mesh.n_bins only reaches the preview via preview_args. The PR card's own example sets n_bins: 200 promising "picture and dataset cannot disagree", yet that file yields a dataset sliced at 60 and a preview at 200 — either plumb n_bins through obj_to_yaml or drop it from MeshSettings.

[1-Bart-1]

@1-Bort-1 fix this

[1-Bort-1]

MINOR: Several new docstrings argue why ("the point of their sharing a block" here; XFoilSolver's "so a comparison ... measures the network"; the file header's "so a caller passes the settings and not a dozen loose numbers"). §4: rationale belongs in the PR description, docstrings say what.

[1-Bart-1]

@1-Bort-1 fix this

[1-Bort-1]

Fixed: the Windows forwarddiff flake — root cause and fix

Thanks for the pushback — you were right that rel_err < 0.1 was too loose and
that this needed a real investigation. I dug into it and found the actual cause;
the tolerance is back to 1e-3.

What the investigation found

The flaky test is test/solver/test_forwarddiff.jl:88 (POLAR_MATRICES), which
compares ForwardDiff (differentiating through the LOOP fixed-point solve) against
FiniteDiff. It was not deterministically broken on Windows: the same commit run
twice gave norm_fd = 2.5669295 vs 2.5670072 and norm_fwd = 2.5731968 vs
2.5670141, one run failing (rel_err = 0.0444) and the other passing.

Two things fell out of that:

1. The solver tolerance does not bound this error. Measured directly, the
   ForwardDiff/FiniteDiff agreement is flat in rtol from 1e-3 down to 1e-13 —
   it sits at ~3.8e-6, the finite-difference truncation floor (which scales
   linearly with the FD step). So the "maximum relative error from the solver
   tolerance" is effectively zero; 1e-3 is already ~250x above the achievable
   floor, and the flake is not a tolerance issue.

2. The generated polar tables are non-reproducible run to run. NeuralFoil's
   forward pass multiplies Float32 matrices with multithreaded BLAS, whose
   reduction order is not bit-reproducible. I measured 6.87e-5 difference between
   1 and 8 threads locally, which matches the ~3e-5 drift in norm_fd across the
   two Windows runs. A tiny table drift that lands a panel's interpolation point
   on a polar knot becomes a ~4% one-sided-vs-central derivative jump — the flake.

The fix

• test/test_data_utils.jl: ram_air_matrix_dir now pins BLAS to a single
  thread while it generates the polar tables (save/restore), so the cached tables
  are bit-identical every run. Verified that single-threaded generation is
  cross-platform reproducible: it now produces norm_fd = 2.5670072429634505,
  bit-identical to the passing Windows run.
• test/solver/test_forwarddiff.jl: restored to the original rel_err < 1e-3
  and the original zeros(4) operating point.
• src/settings_adapters.jl: dropped the "cannot drift" clause from the
  reynolds docstring.

How to review

• The assertion is unchanged from the original PR — the only behavioural change
  in test code is making the table generation deterministic (BLAS.set_num_threads(1)
  around the one obj_to_yaml call in ram_air_matrix_dir).
• CI is green on all platforms, including windows-latest.

Follow-up worth its own issue (not addressed here)

NeuralFoil's Float32 mul! results depend on the BLAS thread count
(~7e-5 across threads). That's below Float32's useful precision for real use,
but if the project ever wants bit-reproducible builds it would need a
deterministic matmul (single-threaded or a fixed-order reduction) in
nn_forward!, not just in this test helper.

Commits

• 320e756 Make the POLAR_MATRICES forwarddiff check robust on Windows
• ae11d48 Make polar generation deterministic so the forwarddiff test stops flaking on Windows
• 9b5edcc Plumb n_bins through obj_to_yaml and trim the settings docstrings

Review just these changes

Task VortexStepMethod.jl-271

[1-Bort-1]

Local full suite: FAIL (0 min, Julia 1.12.7, one cell of the matrix)

  [7] #invokelatest_gr#239
    @ ./reflection.jl:1297 [inlined]
  [8] invokelatest_gr
    @ ./reflection.jl:1289 [inlined]
  [9] maybe_cachefile_lock(f::Base.var"#__require_prelocked##0#__require_prelocked##1"{Base.PkgId, String, Dict{String, Int64}, Base.RefValue{Bool}}, pkg::Base.PkgId, srcpath::String; stale_age::Int64)
    @ Base ./loading.jl:3964
 [10] maybe_cachefile_lock
    @ ./loading.jl:3961 [inlined]
 [11] __require_prelocked(pkg::Base.PkgId, env::String)
    @ Base ./loading.jl:2735
 [12] _require_prelocked(uuidkey::Base.PkgId, env::String)
    @ Base ./loading.jl:2560
 [13] macro expansion
    @ ./loading.jl:2488 [inlined]
 [14] macro expansion
    @ ./lock.jl:376 [inlined]
 [15] __require(into::Module, mod::Symbol)
    @ Base ./loading.jl:2453
 [16] require(into::Module, mod::Symbol)
    @ Base ./loading.jl:2429
 [17] top-level scope
    @ ~/.julia/packages/MakieControlPlots/hXwA9/src/MakieControlPlots.jl:3
 [18] include(mod::Module, _path::String)
    @ Base ./Base.jl:306
 [19] include_package_for_output(pkg::Base.PkgId, input::String, depot_path::Vector{String}, dl_load_path::Vector{String}, load_path::Vector{String}, concrete_deps::Vector{Pair{Base.PkgId, UInt128}}, source::Nothing)
    @ Base ./loading.jl:3106
 [20] top-level scope
    @ stdin:5
 [21] eval(m::Module, e::Any)
    @ Core ./boot.jl:489
 [22] include_string(mapexpr::typeof(identity), mod::Module, code::String, filename::String)
    @ Base ./loading.jl:2952
 [23] include_string
    @ ./loading.jl:2962 [inlined]
 [24] exec_options(opts::Base.JLOptions)
    @ Base ./client.jl:315
 [25] _start()
    @ Base ./client.jl:550
in expression starting at /home/agent/.julia/packages/MakieControlPlots/hXwA9/src/MakieControlPlots.jl:1
in expression starting at stdin:5

[1-Bort-1]

Local full suite: PASS (6 min, Julia 1.12.7, one cell of the matrix)

[1-Bart-1]

@1-Bort-1 why doesn't this use convertdict as well? And is convertdict as safe as manual?

[1-Bort-1]

Fixed

Right — the two new blocks were the only ones parsed by hand. convertdict
(StructMapping) already reads condition: and solver_settings: in that same
file, and it handles every field of mesh:/airfoil: as they stand: the
Vector{Vector{Float64}} rotation from YAML integers, delta_range: null into
Union{Nothing, Vector{Float64}}, table_format from a plain string into the
Symbol, and absent keys falling back to the @with_kw defaults.

Changes

• src/settings.jl — mesh_settings deleted; the wing loop calls
  convertdict(MeshSettings, …) directly. airfoil_settings is now
  convertdict plus the two membership checks, which is the only part of it
  that was ever logic. Net −35 lines.
• test/settings/test_settings.jl — a mistyped key is rejected now instead of
  silently ignored, which is what the hand-written version did.

How KiteUtils does it

StructTypes.Mutable() on Settings; update_settings flattens the YAML
sections into one Dict{Symbol,Any} and StructTypes.constructfrom! fills the
struct; a type YAML cannot express gets a hook —
StructTypes.constructfrom(::Type{MVec3}, vec). Same shape as convertdict,
plus that hook.

The hook is what the rest of this file still lacks. The wing loop and
solver_settings: stay hand-written because of PanelDistribution, Model,
InitialGammaDistribution, the n_groups/grouping_method deprecations and the
use_gamme_prev alias, and StructMapping has no public equivalent of
constructfrom. Making the whole loader generic means swapping StructMapping for
StructTypes the way KiteUtils did — a refactor of code this PR did not add, so I
have left it out. Say the word and it goes up as its own cleanup: PR.

Verification

• test/settings/test_settings.jl 24/24 on the box (exit 0) · docs build
  exit 0 · local full suite PASS (21 min) — the earlier FAIL in 0m note on
  this thread was the runner dying before it started, not a test
• GitHub CI green on all nine checks, Windows and macOS included
• Risk: an unknown key under mesh:/airfoil: now fails the load rather than
  being ignored. Intended — it catches a typo — but it is a behaviour change for
  anyone who had a stray key there.

Commits

• 320e756 Make the POLAR_MATRICES forwarddiff check robust on Windows
• ae11d48 Make polar generation deterministic so the forwarddiff test stops flaking on Windows
• 9b5edcc Plumb n_bins through obj_to_yaml and trim the settings docstrings
• 0694a84 Read the mesh and airfoil blocks with convertdict

Review just these changes

Task VortexStepMethod.jl-271

[1-Bort-1]

_{Superseded by the review further down this thread.}

[1-Bart-1]

Consumer side: BeyondTheSim.jl#5 folds aero_settings.yaml into vsm_settings.yaml against this, and reads obj_file from the mesh: block added in 10ecca3. It cannot merge until this does.

[1-Bart-1]

@1-Bort-1 address the kimi comments

[1-Bort-1]

Fixed

Both findings are one defect: a settings default that shadows a callee's default
with a different number, which slice_args then splats in where the caller never
sees it. obj_to_yaml(obj, dir; slice_args(wing)...) on a wing naming no mesh:
block sliced and wrapped differently from obj_to_yaml(obj, dir) on the same wing.
The values came from examples/V3_neuralfoil.jl, which states them for the V3 —
that kite's choices, not library defaults.

Changes

• src/settings.jl — n_bins 200→60 and wingtip_distance 0.05→0.0 (both
  obj_to_yaml's), clearance 0.0→0.006 and min_concave_radius 0.2→0.02 (both
  ShrinkWrap()'s). Those last two were also documented in [m]; shrink_wrap
  normalises the cloud first, so they are chord fractions.
• Same defect one struct over, unflagged: AirfoilSettings.alpha_range was
  [-15, 3, 90] against obj_to_yaml's -180:1:180, a polar not covering the
  circle. Now [-180, 1, 180].
• test/settings/test_settings.jl — slices ram_air_kite_body.obj twice, through
  slice_args(WingSettings()) and with no keywords, and asserts the sections come
  out equal, plus wrap_method == ShrinkWrap(). It restates no literal, so it
  fails if either side drifts again.

Deliberately left: table_format stays :arrow (it changes how tables are
stored, not the numbers in them), and xtr_upper/xtr_lower stay 0.05 because
NeuralFoilSolver (1.0, free) and XFoilSolver (0.05, tripped) disagree with
each other. MeshSettings cannot just hold a ShrinkWrap and end the duplication
outright — settings.jl is included before AirfoilAero, and wing_geometry.jl
dispatches on VSMSettings, so the two includes cannot swap.

Verification

• test/settings/test_settings.jl 28/28 on the box, rebased onto 10ecca3
  (mesh.obj_file) · docs build exit 0 · local full suite PASS (6 min) ·
  GitHub CI green on all nine checks. The setup job failed first time on
  xvfb-run: error: Xvfb failed to start, before any of our code ran, and
  passed on a re-run of that job alone.
• Risk: alpha_range is the one changed default that costs time — a dataset
  generated with no airfoil: block now sweeps 361 angles rather than 36.

Commits

• 320e756 Make the POLAR_MATRICES forwarddiff check robust on Windows
• ae11d48 Make polar generation deterministic so the forwarddiff test stops flaking on Windows
• 9b5edcc Plumb n_bins through obj_to_yaml and trim the settings docstrings
• 0694a84 Read the mesh and airfoil blocks with convertdict
• 10ecca3 Name the sliced mesh in the wing's mesh block
• a80b8c2 Give the settings blocks the defaults their callees already apply

Review just these changes

Task VortexStepMethod.jl-271

[1-Bort-1]

Independent review (advisory)

Verdict: APPROVE WITH COMMENTS · 2 inline, 0 off the diff

Good

• The additive/defaults claim holds: perpendicular_sections (n_bins=60, rotation=I, wingtip_distance=0.0), ShrinkWrap (clearance=0.006, min_concave_radius=0.02) and LivePolarSettings/NeuralFoilSolver field defaults all match the new MeshSettings/AirfoilSettings defaults, so an unnamed block reproduces an unconfigured call.
• reynolds(set, wing) reads density/mu from solver_settings (verified present at settings.jl:188/201) and matches the solver's own density·v·c/mu definition, so Reynolds now has one source for these callers.
• airfoil_settings fails loudly with ArgumentError on an unknown solver or table_format, and LivePolarSettings(airfoil) now pulls model_size/n_crit from the same block the tables came from.
• Exports, docs wiring (types.md, functions.md, private_functions.md) and tests covering both blocks, ranges, reynolds, solver selection, live/table agreement and slice/preview args are all in place.

Not good

• test/test_data_utils.jl:50 — The BLAS single-threading change (and the LinearAlgebra import) fixes NeuralFoil bit-reproducibility, which is unrelated to this settings PR and belongs in its own cleanup PR per the one-idea rule.
• test/settings/test_settings.jl:83 — @test_throws Exception on the typo'd key 'n_crt' is too broad to protect the intended 'unknown key rejected' behaviour; it passes on any error (or none thrown by a lax convertdict), so it should name the expected exception type.
• rotation_matrix uses permutedims(reduce(hcat, mesh.rotation)) to stack row-vectors as rows, correct but convoluted for what a stack/vcat+transpose would say plainly.
• AirfoilSettings defaults xtr_upper/lower to 0.05 (XFoil's default) not 1.0 (NeuralFoilSolver's free-transition default), so a NeuralFoil user adopting the block gets forced transition where a bare NeuralFoilSolver() would not — documented but subtle.
• The MeshSettings/AirfoilSettings docstrings run far past the 1-4-line prose guidance and embed 'why' (e.g. 'so a wing naming no mesh block slices as an unconfigured call', obj_file 'cannot be given alongside one'), which the rubric wants in the PR description instead.

_{opencode, rubric CLEAN_CODE.md. A different lab from the implementer
on purpose: a reviewer sharing its blind spots would not flag its mistakes.}

[1-Bort-1]

MINOR: The BLAS single-threading change (and the LinearAlgebra import) fixes NeuralFoil bit-reproducibility, which is unrelated to this settings PR and belongs in its own cleanup PR per the one-idea rule.

[1-Bort-1]

MINOR: @test_throws Exception on the typo'd key 'n_crt' is too broad to protect the intended 'unknown key rejected' behaviour; it passes on any error (or none thrown by a lax convertdict), so it should name the expected exception type.