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Correct the slit-radiation sign in the slow-sound absorber and generalize the diffuser obliquity factor (#349)
* Fix slit-radiation sign, generalize Kirchhoff obliquity, record paper errata
The slit-to-free-air radiation correction of the slow-sound absorber was
transcribed with the papers' printed -iw sign, which in the e^{+jwt}
convention of the library acts as a negative mass and raises the slit-panel
resonance (378.6 to 386.8 Hz for the documented base geometry) where an
added radiation mass must lower it (370.8 Hz). The term is now conjugated
like the Stinson duct series of the same model, with the direction and the
shifted peak pinned by a regression test, and both source misprints (the
sign and the 4-vs-64 duct-series constant) are recorded in the errata
registry. The committed slow-sound figures are regenerated; the
critical-coupling design they show self-compensates to alpha = 1, but the
solved cavity length moves from 48.3 mm to 44.7 mm.
The diffuser far-field predictor now uses the symmetric Kirchhoff obliquity
factor (cos theta + cos psi)/2 for oblique sources, which reduces exactly
to the Cox and D'Antonio Eq. (9.32) normal-incidence form at psi = 0, so
all normal-incidence anchors are unchanged.
Also: the EN 29052-1 low-resistivity warning now echoes the clause 8.2
requirement to state the estimated error in the test report, and the
ISO 9053-2 volume-flow helper documents the normative 6.2 form against the
Annex A.2 rms variant.
* Update the porous-absorbers misprint count for the new errata entries
The page's sources now have five recorded misprints (Maa Eq. (5b), two in
Attenborough & Van Renterghem 2e, and the two Jimenez et al. entries); the
English and Spanish guides are kept in step.
Replace the ISO 17497-2 diffusion oracle with published-provenance data (#348)
The committed 37-receiver polar arc in tests/reference_data.py is now
generated by the library's own Fraunhofer far-field model for a published
geometry: the N = 7 QRD, 6 periods, 3.6 m wide, 0.2 m deep row of
Cox & D'Antonio, Acoustic Absorbers and Diffusers, 3rd ed., Appendix B
(the commercial N = 7 QRD of Hargreaves, Cox, Lam & D'Antonio, JASA 108(4),
1710-1720, 2000, Table I). The arc is an arithmetic oracle for ISO 17497-2
Formulas (5)/(7): d = 0.1099, flat reference d = 0.0049, d_n = 0.1055,
recomputed exactly from the committed rounded levels.
A new external third-party anchor pins the model's one-third-octave
band-averaged normalised diffusion to the published Appendix B 2D BEM values
for that row at normal incidence in the 200-400 Hz bands (agreement within
0.01, asserted at +/-0.015) in the tests and in four new conformance rows.
Across the full published 100-5000 Hz range the model-vs-BEM mean absolute
deviation is about 0.09, documented everywhere as a low-band anchor.
The previous in-house COMSOL simulation arc and its numbers are removed from
the tests, the conformance report, the surface-scattering guide (EN/ES), the
theory pages and the diffusion_polar figure, which now all use the same
published-geometry prediction.
docs: refresh install extras and landing pages to current library scope (#274)
* docs: refresh install extras and landing pages to current library scope
The install docs listed only the plot, perf and full extras; add the report
extra (reportlab + svglib, required for the .report() PDF fiches) and fix the
stale 'both' comment on full in the site getting-started pages (EN/ES),
docs/getting-started.md and the README install line.
Refresh the landing pages, which predated most of the library:
- Site index (EN/ES): hero and cards now describe all fifteen domain
namespaces, the 371 conformance checks across 46 domains and 235 standards,
bilingual .plot() figures and the normative .report() PDF fiches.
- Getting started (EN/ES): note that the metrology core is one of fifteen
domains and link Why phonometry and the conformance report.
- Why phonometry (EN/ES): state the current conformance scale beyond the
metrology-core sample table.
- README: current toolkit description, missing domain highlights (hearing,
materials, vibration, aircraft, underwater, electroacoustics, noise control,
FDTD, fiches), five sound-power routes, G weighting, and twelve to fifteen
namespaces.
- Shorten the junction-transmission page titles (EN/ES) to satisfy the
70-character html-validate limit.
* docs: name all standards bodies on the landing description and tighten the ES card wording
Add ANSI, DIN and ECAC/CEAC to the standards-body enumeration in the site
index description (both languages), keep 'con estado' for the stateful block
processing in the Spanish card, and use the Spanish 'Doc 29/32 de la CEAC'
form already used by the Spanish guides.
docs: refresh install extras and landing pages to current library scope (#274)
* docs: refresh install extras and landing pages to current library scope
The install docs listed only the plot, perf and full extras; add the report
extra (reportlab + svglib, required for the .report() PDF fiches) and fix the
stale 'both' comment on full in the site getting-started pages (EN/ES),
docs/getting-started.md and the README install line.
Refresh the landing pages, which predated most of the library:
- Site index (EN/ES): hero and cards now describe all fifteen domain
namespaces, the 371 conformance checks across 46 domains and 235 standards,
bilingual .plot() figures and the normative .report() PDF fiches.
- Getting started (EN/ES): note that the metrology core is one of fifteen
domains and link Why phonometry and the conformance report.
- Why phonometry (EN/ES): state the current conformance scale beyond the
metrology-core sample table.
- README: current toolkit description, missing domain highlights (hearing,
materials, vibration, aircraft, underwater, electroacoustics, noise control,
FDTD, fiches), five sound-power routes, G weighting, and twelve to fifteen
namespaces.
- Shorten the junction-transmission page titles (EN/ES) to satisfy the
70-character html-validate limit.
* docs: name all standards bodies on the landing description and tighten the ES card wording
Add ANSI, DIN and ECAC/CEAC to the standards-body enumeration in the site
index description (both languages), keep 'con estado' for the stateful block
processing in the Spanish card, and use the Spanish 'Doc 29/32 de la CEAC'
form already used by the Spanish guides.