Fixes:
- fix loading spline models with more than five knots (Issue #985)
- improved SplineModel to explicitly allow more knots, make it easier to evaluate and save/reload (Issue #985 PR #989, Paul Müller)
- improvements to adding Parameters.
- support Model functions with "barestar" syntax (PR #982)
- fix several related problems with providing a Jacobian function, especially for consistency across solvers (including least_squares), and for pickling (PR #973 Ville Yrjänä)
- fix Step and Rectangle Models to allow a negative value for sigma, indicating a downward step (PR #970)
Build, Maintenance:
- update issue templates
- add test for consistent init_fit and best_fit for saved/looded SplineModel
- fix NumPy v2 DeprecationWarning
- uppdate SciPy/NumPy dependencies.
- remove numexpr dependency (again)
- drop support for Python 3.8, add Python 3.13
- asteval no longer raises NameError to Python, so we catch exceptions from asteval when creating parameters.
- avoid setting
stderrtoNonefor uncertainties calculations.
Documentation and Examples:
- add example with uncertainties in both x and y (#992)
- make sign of residual calculations in model.py consistent with documentation (Discussion #986, PR#987, Timothy-J-Warner)
- add example fitting multiple datasets using Model interface (Discussion #904, PR #967, mstekiel)
- tweaks to 'sphinx-gallery' settings.
- update names of the documentation examples in Gallery