explicitly disallow multitaper in presence of bad annotations (mne-to…

…ols#12535)

doc/changes/devel/12535.bugfix.rst

@@ -0,0 +1 @@
+Calling :meth:`~mne.io.Raw.compute_psd` with ``method="multitaper"`` is now expressly disallowed when ``reject_by_annotation=True`` and ``bad_*`` annotations are present (previously this was nominally allowed but resulted in ``nan`` values in the PSD). By `Daniel McCloy`_.

mne/io/base.py

@@ -2197,7 +2197,9 @@ def compute_psd(
         Parameters
         ----------
         %(method_psd)s
-            Default is ``'welch'``.
+            Note that ``"multitaper"`` cannot be used if ``reject_by_annotation=True``
+            and there are ``"bad_*"`` annotations in the :class:`~mne.io.Raw` data;
+            in such cases use ``"welch"``. Default is ``'welch'``.
         %(fmin_fmax_psd)s
         %(tmin_tmax_psd)s
         %(picks_good_data_noref)s

mne/time_frequency/spectrum.py

@@ -1132,6 +1132,12 @@ def __init__(
             data = self.inst.get_data(
                 self._picks, start, stop + 1, reject_by_annotation=rba
             )
+            if np.any(np.isnan(data)) and method == "multitaper":
+                raise NotImplementedError(
+                    'Cannot use method="multitaper" when reject_by_annotation=True. '
+                    'Please use method="welch" instead.'
+                )
+
         else:  # Evoked
             data = self.inst.data[self._picks][:, self._time_mask]
         # set nave

mne/time_frequency/tests/test_spectrum.py

@@ -24,6 +24,9 @@ def test_compute_psd_errors(raw):
         raw.compute_psd(foo=None, bar=None)
     with pytest.raises(ValueError, match="Complex output is not supported in "):
         raw.compute_psd(output="complex")
+    raw.set_annotations(Annotations(onset=0.01, duration=0.01, description="bad_foo"))
+    with pytest.raises(NotImplementedError, match='Cannot use method="multitaper"'):
+        raw.compute_psd(method="multitaper", reject_by_annotation=True)
 
 
 @pytest.mark.parametrize("method", ("welch", "multitaper"))