docs: Correct tolerance default attribution

[Hayden Anderson (haydena7)]

Motivation

The tolerances guide states that the default abs_tol=1e-08 / rel_tol=1e-05 match Python's math.isclose defaults. They don't — math.isclose defaults to rel_tol=1e-09, abs_tol=0.0. The values actually match polars.testing.assert_frame_equal.

The error points in the risky direction: a reader trusting the guide would believe diffly is stricter (~9 significant figures) than it is (~5).

Changes

• Reword the "Default behavior" paragraph in docs/guides/features/tolerances.ipynb to attribute the defaults to polars.testing.assert_frame_equal.

Markdown cell only; no cells were executed and no outputs changed. The compare_frames docstring note that the implementation mirrors math.isclose is left as-is, since that statement is about the formula and is correct.

[Copilot]

🟡 Changes recommended

The updated paragraph includes a potentially confusing comparison to polars.Expr.is_close defaults even though Diffly calls Expr.is_close with explicit tolerances.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

Updates the tolerances documentation to correctly attribute Diffly’s default float tolerances to Polars testing utilities, preventing readers from misinterpreting how strict Diffly’s default comparisons are.

Changes:

• Reworded the “Default behavior” paragraph to attribute abs_tol=1e-08 / rel_tol=1e-05 to polars.testing.assert_frame_equal.
• Added an explanatory note contrasting these defaults with Python’s math.isclose defaults.

File summaries

File	Description
docs/guides/features/tolerances.ipynb	Corrects documentation text about default tolerance provenance.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 1
• Review effort level: Lite

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[Oliver Borchert (borchero)]

Thank you!