Setup for 1.0.0 release

[MitchellThompkins]

Summary

I started working on this set of changes a number of years ago and have only gotten around to completing the implementation recently. This adds a numerically accurate eigenvalue and eigenvector solver, many more tests (compile-time and run-time against both Octave generated references and Eigen respectively), examples, and some theory discussion, along with the CI/CD, build system, and documentation infrastructure needed to support a proper public release.

CI/CD

• Rewrote main.yml from a single job to a matrix pipeline: separate lint, build-and-test (GCC + Clang), cross-compile (ARM GCC + Clang), check-generated, and dc-motor-fail jobs.
• Added docs.yml to build and deploy the MkDocs + Doxygen site to GitHub Pages on pushes to main.
• Container images are now tagged by date (from .env) and SHA; a CI guard enforces that Dockerfile and .env change together.
• Added a weekly scheduled run.

Build system

• CMakeLists.txt: upgraded to C++17, renamed project to consteig, added strict consteig_warnings interface target (-Wall -Wextra -pedantic -Werror + extended set), CONSTEIG_BUILD_TESTS and CONSTEIG_COMPILE_ONLY options, consteig_raise_compiler_limits() helper, and FetchContent-compatible structure.
• Makefile: added per-compiler targets (build.gcc, test.clang, etc.), cross-compile targets (cross.arm-gcc, cross.arm-clang), check-format, generate-test-cases, check-generated, test-dc-motor-fail, and profile.
• Dockerfile: updated Alpine 3.14 -> 3.23, added ARM GNU toolchain (15.2), clang-extra-tools, octave, and uv.

Cross-compilation

• Added cmake/toolchains/arm-none-eabi-gcc.cmake and arm-none-eabi-clang.cmake for bare-metal ARM targets.
• CONSTEIG_COMPILE_ONLY mode compiles to .o files only (no linker step), exercising all static_assert checks without a C runtime.

Library

• Expanded eigen value solver to route symmetric and non-symmetric matrices to different algorithms. The old solver used a simple explicit single-shift QR loop with a hardcoded convergence threshold and no preprocessing. The new implementation routes symmetric matrices through a single-shift QR path (sufficient since real eigenvalues are guaranteed) and non-symmetric matrices through the full Francis implicit double-shift QR algorithm (with both matrix balancing (Parlett & Reinsch 1969) and Hessenberg reduction as preprocessing. The double-shift path handles complex conjugate pairs simultaneously using real arithmetic, with Wilkinson shifts for quadratic convergence, LAPACK-style exceptional shifts every 10 iterations to prevent stalling, and a dual-mode deflation criterion (relative to matrix norm + absolute against machine epsilon). The deflation was critical for keeping compile times tractable across the expanded robustness test suite; otherwise compilation times exploded but with no real improvement on accuracy.

• The old solver used a simple explicit single-shift QR loop with a hardcoded convergence threshold and no preprocessing. The new implementation uses the Francis implicit double-shift QR algorithm: the input is first balanced (Parlett & Reinsch 1969) and reduced to Hessenberg form, then a bulge-chasing step handles complex
  conjugate pairs simultaneously using real arithmetic, with Wilkinson shifts for quadratic convergence, LAPACK-style exceptional shifts every 10 iterations to prevent
  stalling, and a dual-mode deflation criterion (relative + absolute against machine epsilon) that was critical for keeping compile times tractable across the expanded
  robustness test suite.

• New consteig_types.hpp introducing consteig::Size; replaced all size_t uses in library and test code.

• consteig_options.hpp: expanded with Doxygen @defgroup config documentation; added CONSTEIG_MAX_ITER, CONSTEIG_BALANCE_CONVERGENCE_THRESHOLD, E_CONST, PI_CONST, CONSTEIG_TRIG_MAX_ITER, and CONSTEIG_USE_LONG_DOUBLE.

• array/array.hpp: added const T* data() overload and full Doxygen comments.

• eigen/eigen.hpp, matrix/, math/: reformatted to Microsoft/clang-format style; explicit casts for Eigen indexing; hardcoded tolerances replaced with named constants.

Tests

• Significantly expanded generated test suite (eigen/tests/generated_*): adds robustness categories including defective, nearly defective, clustered eigenvalues, companion, and Hamiltonian matrices.
• All tests updated for strict-warning builds.
• dc-motor-fail test verifies that bad PID gains trigger a static_assert at build time.

Documentation

• New MkDocs + Material site under docs/: getting-started guide, configuration reference, decompositions/eigensolvers/math-functions/matrix guides, example walkthroughs (Butterworth filter, DC motor control, population dynamics), verification and performance pages.
• Doxygen API reference generated and co-deployed to GitHub Pages.

Legal / project

• Added LICENSE (Apache 2.0) and NOTICE (attributing GCE-Math).
• New README.md, AGENT.md (with CLAUDE.md/GEMINI.md symlinks), .clang-format, .coderabbit.yaml, .gitattributes (LFS for profiling/docs PNGs).

Octave

• Reorganized development scripts into octave/development_scripts/.
• generate_test_cases.m updated to produce the expanded robustness test cases.
• New generate_profiling_cases.m for compile-time profiling.

Profiling

• New profiling infrastructure: profiling/CMakeLists.txt, run_profiling.sh, analyze_results.py, GCC 15.2.0 baseline results.

[MitchellThompkins]

@coderabbitai summary

[coderabbitai]

✅ Actions performed

Summary regeneration triggered.

[MitchellThompkins]

@coderabbitai summary

[coderabbitai]

✅ Actions performed

Summary regeneration triggered.