Release 0.6.1

[utensil]

For motivation and backstory, see this comment.

What's in it

Bug fixes

• is_blade() now correctly handles null vectors and null blades (Multivector method .is_blade() will fail for null multivectors #537, merged via fix(mv): is_blade() now correctly handles null vectors and null blades #582)
• Lt accepts ImmutableDenseMatrix (Lt does not accept ImmutableDenseMatrix from SymPy 1.13 #567, merged via fix(lt): accept ImmutableDenseMatrix in Lt.__init__ (#567) #569)
• Multivector display avoids the SymPy 1.13 simplification regression outside the original curvilinear-coordinate example (fix: avoid slow simplification during multivector display #598)

Infra / tooling

• Migrate to pyproject.toml / PEP 517 (build: migrate to pyproject.toml, fix deprecated CI wheel build (#586) #587)
• CI now tests Python 3.10, 3.11, 3.12; dropped 3.8/3.9 (ci: bump Python to 3.10-3.12, drop 3.8/3.9 (#564) #565)
• CI keeps independent master and tag runs from cancelling each other (ci: fix concurrency group causing master badge to show cancelled #595)

Docs / support

• GAlgebraPrimer.pdf updated to Sep 2023 revision (docs(macdonald): update GAlgebraPrimer.pdf to September 2023 version #577)
• Notebook outputs refreshed for SymPy 1.13 (fix(notebooks): refresh outputs for SymPy 1.13 printing changes (#568) #570)
• Dev guides for bumping Python/SymPy and release process (docs: update README Python prereqs; add dev guides for bumping Python and SymPy (#571) #572)
• Corrected the DOI badge and citation metadata to use the permanent Zenodo concept DOI (docs: fix DOI badge and citation metadata #599)

Pre-release todos

• Merge build: migrate to pyproject.toml, fix deprecated CI wheel build (#586) #587 (pyproject.toml migration)
• Update changelog: add entries for test(mv): expand and reorganize is_blade coverage (#537) #585 and build: migrate to pyproject.toml, fix deprecated CI wheel build (#586) #587, reorganize
• Merge and validate chore: prepare 0.6.1rc2 #600 / v0.6.1rc2 after post-rc fixes fix: avoid slow simplification during multivector display #598 and docs: fix DOI badge and citation metadata #599

Then follow doc/dev/release-process.md.

[utensil]

0.6.1 is motivated by Bumping Python to 3.12, SymPy to 1.13 (both are recent but not latest versions, easier for test/tooling migration).

A new mechanism to update and check notebook output is introduced, now we can ensure the change of notebook outputs (which will be used in tests via nbval) are cosmetic, otherwise handle accordingly with extra caution on math and code correctness.

We have also addressed performance or test coverage regression, introduced by the bump.

Along the way, we documented some dev process including bumping both and releasing a new version. Some initial tooling bump is also done. We also manage to fix a few bugs that are left by 0.6.0.

0.6.0 was meant to be released in 2025, most of the meaningful work was done in 2024, but there are too many loose ends that require careful treatment. 2025 was a busy year for me, with many new explorations, and 3 months of broken rib.

Fortunately, I've finally made some time to finish the work for releasing 0.6.0, on April 1 (an unfortunate date but I didn't want to wait any longer). Immediately there are many follow-up polish work that are low-hanging fruit, hence a quick 0.6.1 release in the same week.