NEWS

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acousticTS 2026.3.0

What's Changed

⚠️ Breaking Changes

• The DCM model has been fully deprecated due to its 1) misleading name and 2) limited scope. It has been superseded by TRCM, which uses an adjusted implementation that allows for both straight and bent cylinder geometries.
• The DWBA_curved and SDWBA_curved models have been deprecated. It is now expected that users explicitly apply brake to their shapes (i.e., adds curvature) prior to using the standard DWBA and SDWBA models.
• The MSS_anderson model has been deprecated and replaced with SPHMS.
• The high_pass_stanton model has been deprecated and replaced with HPA.
• The MSS_goodman_stern model has been deprecated and replaced with ESSMS.
• Additional geometry and class guardrails have been added across the package. Some legacy workflows may now error if the supplied shape, scatterer class, or boundary assumptions are incompatible with the selected model.

New features and enhancements :sparkles:

Software :desktop_computer:

New & updated models :pencil:

• SPHMS: Modal-series solution for canonical spherical targets across multiple supported boundary conditions.
• FCMS: Modal-series solution for finite cylinders across multiple supported boundary conditions.
• PSMS: Modal-series solution for prolate spheroids across multiple supported boundary conditions.
• SOEMS / calibration: The solid elastic sphere workflow has been broadened and documented as a general solid-elastic-sphere family rather than only a calibration-sphere workflow. calibration remains available as a compatibility alias.
• ESSMS: Modal-series solution for elastic-shelled spheres.
• BCMS: Modal-series solution for finite, bent cylinders.
• ECMS: Modal-series solution for solid elastic finite cylinders.
• KRM: Now incorporates the breathing-mode modal-series calculation for ka < 0.15 and has been updated to better align with alternative body sound-speed assumptions.
• HPA: Expanded usable geometries and now includes the Johnson (1977) formulation.
• TRCM: The two-ray cylinder model now supports both straight and bent cylinders.
• PCDWBA: Phase-compensated distorted-wave Born approximation for bent weakly scattering targets.
• BBFM: Composite flesh-plus-backbone model for swimbladder-less fish-like targets, treating the backbone as a solid elastic scatterer.
• VESMS (VESM family): Viscous-elastic layered-sphere model for gas-core, shell, and viscous-layer targets.
• TMM: Transition-matrix framework for monostatic and angle-dependent scattering of spheres, prolate spheroids, oblate spheroids, and guarded finite-cylinder branches.

Numerical methods :calling:

• Cylindrical and spherical Bessel functions of the first, second, and third kinds were overhauled and expanded, including broader support for orders, purely imaginary arguments, and public $k^{\text{th}}$ derivative helpers such as jcdk(), hcdk(), jsdk(), and ysdk().
• Full public support for prolate spheroidal angular and radial wave functions via Smn() and Rmn(), including derivatives.
• Public Legendre support now includes both the first and second kinds, including Pn(), Pndk(), Qn(), and Qndk().
• New numerical helpers such as gauss_legendre() and related modal/scattering utilities were added to support higher-level model implementations.

Workflow, geometry, and extensibility :gear:

• Shape- and scatterer-generation workflows were substantially streamlined and reorganized.
• simulate_ts() provides parameter-sweep and repeated-realization workflows for TS simulation.
• canonicalize_shape() converts arbitrary shapes into canonical surrogates such as spheres, prolate spheroids, oblate spheroids, and cylinders.
• reforge() supports resizing and reparameterizing supported scatterer objects.
• extract() provides a consistent way to pull nested components and parameters from supported objects.
• New model-registry helpers make it possible to register user-defined models for direct use with the broader acousticTS workflow:
  • available_models()
  • register_model()
  • unregister_model()
  • reset_model_registry()
• The TMM workflow now includes additional post-processing and diagnostics helpers, including:
  • tmm_scattering()
  • tmm_scattering_grid()
  • tmm_products()
  • tmm_bistatic_summary()
  • tmm_average_orientation()
  • tmm_orientation_distribution()
  • tmm_diagnostics()

Other enhancements :pig2: :lipstick:

• New elastic-property helpers were added, including lame(), pois(), bulk(), young(), and shear().
• Core acoustic utilities such as wavenumber(), compressibility(), transmission_coefficient(), degrees(), and radians() were expanded and cleaned up.
• Example-data support was improved, including bundled fish and benchmark objects used throughout the documentation and validation workflows.

Validation and benchmarking :white_check_mark:

• A formal validation and benchmarking registry was added to track benchmarked, validated, partially validated, unvalidated, and experimental model families.
• A new benchmark_ts dataset was added to support canonical comparison ladders across modal-series families.
• Reproducible implementation-figure and comparison pipelines were added for documented model families.
• Cross-software and cross-reference validation coverage was expanded across models such as SPHMS, FCMS, PSMS, SOEMS, KRM, HPA, PCDWBA, VESMS, and TMM.
• The pkgdown model library now exposes family-level validation badges and supporting summaries directly in the site.

Performance :rocket:

• Major compiled backends were added in C++ and Fortran, substantially improving performance across special functions and core models. This affects the Bessel functions, Legendre functions, spheroidal wave functions, DWBA / SDWBA, PSMS, ESSMS, TMM, and VESMS.
• Adaptive methods were added for SOEMS / calibration, giving users more control over the balance between speed and precision.
• Optional modal-truncation controls such as m_limit were added or expanded across modal-series solutions, allowing users to trade precision for speed more explicitly at higher ka.

Documentation :open_book:

• The package documentation was fully reorganized into a pkgdown site with model-family overview, theory, and implementation pages.
• A large new vignette set was added, including package primers, model selection, numerical foundations, notation, material properties, boundary conditions, example data, shape/scatterer construction, running models, comparing models, plotting results, simulation sweeps, validation benchmarks, and model creation workflows.
• Model-family landing pages and the model library were added to make the package structure and validation status easier to navigate.
• Figure-generation and vignette-rendering workflows were standardized and expanded to support the implementation and validation documentation.

Bug-fixes :bug:

• DWBA / SDWBA: End-on incidence for some shapes, especially cylinders, could previously return Inf values for $\sigma_\text{bs}`. This behavior was fixed.
• Numerous fixes were applied across shape generation, scatterer handling, plotting, model dispatch, documentation rendering, and pkgdown build behavior.
• Several numerical edge cases and validation pathways were tightened across the special-function and modal-series infrastructure.

Testing and QA :test_tube:

• The automated test suite was expanded substantially across models, special functions, geometry helpers, simulation workflows, validation utilities, and pkgdown helpers.
• Additional validation-specific and implementation-specific regression tests were added to support the new model families and compiled backends.

Infrastructure :building_construction:

• GitHub Actions workflows were expanded to cover R CMD check, pkgdown builds, documentation generation, implementation figures, pre-CRAN checks, rhub, and test coverage.
• Package metadata and release-support files were improved, including NEWS.md and CITATION.cff.
• Internal package organization was significantly restructured, including model dispatch, utilities, plotting helpers, validation helpers, and compiled source layout.

Full Changelog: https://github.com/brandynlucca/acousticTS/compare/v.1.0...v.2026.03.0

acousticTS 2.0.7

• Correct cylindrical Bessel functions on the imaginary axis and the upper side of the negative real axis branch cut.
• Stabilize spherical Bessel sequences near zeros of the order-zero function.
• Return correctly indexed angular matrices from Smn() when evaluating paired mode vectors at multiple angular coordinates.
• Return the finite minimum-norm solution for zero-rank SVD systems.

acousticTS 2.0.6 (2026-09-26)

• Accommodate the experimental LLVM Flang 23 R-devel toolchains, including their compiler diagnostics and target-specific intrinsic-module location.
• Unwrap the short plotting example and remove optional quad precision examples that require build-specific support, retaining runnable double precision examples.
• Credit the authors of adapted upstream prolate_swf code in Authors@R, with comments distinguishing upstream authorship from package development.
• Simplify the license declaration to GPL-3 and remove the redundant top-level LICENSE file, preserving upstream copyright and MIT license notices.

acousticTS 2.0.4

• Replace invalid relative links in the installed boundary-conditions vignette.

acousticTS 2.0.3

• Submission to CRAN

acousticTS 2.0.2

What's Changed

• Update DESCRIPTION by @brandynlucca in https://github.com/brandynlucca/acousticTS/pull/49
• Reorganize and reformat pkgdown documentation by @brandynlucca in https://github.com/brandynlucca/acousticTS/pull/50
• Address plotting bug for FLS-class objects by @brandynlucca in https://github.com/brandynlucca/acousticTS/pull/50
• Adjust pkgdown documentation by @brandynlucca in https://github.com/brandynlucca/acousticTS/pull/50
• Fix compilation-related warnings and bugs when running the Rhub testing suite by @brandynlucca in https://github.com/brandynlucca/acousticTS/pull/51
• Modified GitHub Actions workflows to include additional containers and checks by @brandynlucca in https://github.com/brandynlucca/acousticTS/pull/51
• Documentation styling and tidying by @brandynlucca in https://github.com/brandynlucca/acousticTS/pull/51

Full Changelog: https://github.com/brandynlucca/acousticTS/compare/v.2.0.1...v.2.0.2

acousticTS 2.0.1

What's Changed

• Enhance and apply bug-fixes to Scatterer-reforge and other shape manipulation methods by @brandynlucca in https://github.com/brandynlucca/acousticTS/pull/41, https://github.com/brandynlucca/acousticTS/pull/43, https://github.com/brandynlucca/acousticTS/pull/48
• Improve C++ backend for T-matrix methods by @brandynlucca in https://github.com/brandynlucca/acousticTS/pull/45, https://github.com/brandynlucca/acousticTS/pull/47
• Implemented and tweaked various C++ internals for greater flexibility and adaptability for future model releases, such as the current (very) experimental elastic-shelled PSMS model by @brandynlucca in https://github.com/brandynlucca/acousticTS/pull/44
• Improve pkgdown documentation by @brandynlucca in https://github.com/brandynlucca/acousticTS/pull/45, https://github.com/brandynlucca/acousticTS/pull/46, https://github.com/brandynlucca/acousticTS/pull/47

Full Changelog: https://github.com/brandynlucca/acousticTS/compare/v.2026.03.0...v.2.0.1

acousticTS 1.0.1

• Added a NEWS.md file to track changes to the package.