BUG: Raise early on non-finite values in PSD (Welch) and ICA.fit (Fix…

[zhijingz]

…es #13364)

Reference issue (if any)

Fixes #13364

What does this implement/fix?

psd_array_welch

• Added an explicit early check for Inf values inside the analyzed span.
• Replaced an internal assert with a user-facing ValueError when NaN masks are not aligned across channels.
• Retained existing intended behavior that allows “sentinel” NaNs — aligned across channels — to mark annotation boundaries without error.

ICA.fit

• Added an early ValueError guard when input data contain any NaN or Inf, producing a clear message instead of downstream runtime warnings.

Additional information

[welcome]

Hello! 👋 Thanks for opening your first pull request here! ❤️ We will try to get back to you soon. 🚴

[zhijingz]

Hi! First-time contributor here. I’ve rebased on current main, pre-commit passes locally, and targeted tests are green:

pytest -q mne/time_frequency/tests -k psd → 21 passed, 6 skipped
pytest -q mne/preprocessing/tests -k ica → 1 passed

Could someone please approve CI to run on this PR? Thanks!

[larsoner]

Suggested change

	in PSD (Welch) and in ICA.fit, avoiding deep assertion failures (GH-13364).
	in PSD (Welch) and in ICA.fit, avoiding deep assertion failures, by :newcontrib:`First Last`

then also add to doc/changes/names.inc

[zhijingz]

Hi, I revised the contritbution doc - anything else I need to do for the workflow to be approved?

[drammock]

I made a few comments/suggestions about specific bits of the code/tests. Additional high-level comments:

#13364 (comment) suggested that we error for ICA.fit when there are NaNs present, but for PSD we should warn if NaNs are on specific channels and compute the PSD for the other channels that have good data. I see two new ValueErrors and no new warnings in the time_frequency code, so it seems like you're doing something different from what @larsoner recommended.

[drammock]

Suggested change

	Fail early with a clear error when non-finite values (NaN/Inf) are present
	in PSD (Welch) and in ICA.fit, avoiding deep assertion failures by :newcontrib: `Emma Zhang`
	Improved error message when non-finite values (NaN/Inf) are detected in calls to
	:meth:`inst.compute_psd(method="welch") <mne.io.Raw.compute_psd>` or
	:meth:`ICA.fit() <mne.preprocessing.ICA.fit>`, by :newcontrib:`Emma Zhang`.

[drammock]

Suggested change

	rng = np.random.RandomState(1)
	data = rng.randn(4, 1000)
	rng = np.random.default_rng(1)
	data = rng.standard_normal(size=(4, 1000))

this is the pattern recommended for new code; see https://numpy.org/doc/stable/reference/random/index.html#random-quick-start

[drammock]

Suggested change

	with pytest.raises(ValueError, match=r"Input data contains non[- ]?finite values"):
	with pytest.raises(ValueError, match=r"Input data contains non-finite values"):

since you wrote the error message, we know exactly what it says; no need for the [- ]?

[drammock]

see prior comment re: default_rng and standard_normal

[drammock]

similar comment as above: avoid complicated regex in the match parameter; we wrote the error message so we can pull out a distinctive string of words from it and match on that. That approach makes maintenance easier (you can copy/paste/search on the match string to find the place in the codebase where the error is raised)

[drammock]

the filename needs to match the PR, not the issue. so move this file to 13486.bugfix.rst