Better splinemodel

[newville]

This explicitly implements the Spline model function, instead of overwriting SplineModel.eval(), so that a simple evaluation will work, which is more consistent and needed when loading a saved Model.

Description

This should solve #990

Type of Changes

• Bug fix
• New feature
• Refactoring / maintenance
• Documentation / examples

Tested on

Python: 3.12.8 | packaged by conda-forge | (main, Dec 5 2024, 14:25:12) [Clang 18.1.8 ]

lmfit: 1.3.2.post23+gec300195, scipy: 1.15.1, numpy: 1.26.4, asteval: 1.0.6, uncertainties: 3.2.2

Verification

Have you

• included docstrings that follow PEP 257?

• referenced existing Issue and/or provided relevant link to mailing list?

• verified that existing tests pass locally?

• verified that the documentation builds locally?

• squashed/minimized your commits and written descriptive commit messages?

• added or updated existing tests to cover the changes?
• updated the documentation and/or added an entry to the release notes (doc/whatsnew.rst)?
• added an example?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.19%. Comparing base (54a119f) to head (ec8c1d8).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #991      +/-   ##
==========================================
+ Coverage   92.59%   93.19%   +0.59%     
==========================================
  Files          10       10              
  Lines        3836     3836              
==========================================
+ Hits         3552     3575      +23     
+ Misses        284      261      -23     

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[newville]

any objections to merging this?