Fix EpochsTFR.add_channels() (#12616)

doc/changes/devel/12616.bugfix.rst

@@ -0,0 +1 @@
+Fix adding channels to :class:`~mne.time_frequency.EpochsTFR` objects, by `Clemens Brunner`_.

mne/channels/channels.py

@@ -696,6 +696,7 @@ def add_channels(self, add_list, force_update_info=False):
         # avoid circular imports
         from ..epochs import BaseEpochs
         from ..io import BaseRaw
+        from ..time_frequency import EpochsTFR
 
         _validate_type(add_list, (list, tuple), "Input")
 
@@ -708,6 +709,9 @@ def add_channels(self, add_list, force_update_info=False):
         elif isinstance(self, BaseEpochs):
             con_axis = 1
             comp_class = BaseEpochs
+        elif isinstance(self, EpochsTFR):
+            con_axis = 1
+            comp_class = EpochsTFR
         else:
             con_axis = 0
             comp_class = type(self)

mne/time_frequency/tests/test_tfr.py

@@ -943,6 +943,23 @@ def test_add_channels():
     pytest.raises(ValueError, tfr_meg.add_channels, [tfr_meg])
     pytest.raises(TypeError, tfr_meg.add_channels, tfr_badsf)
 
+    # Test for EpochsTFR(Array)
+    tfr1 = EpochsTFRArray(
+        info=mne.create_info(["EEG 001"], 1000, "eeg"),
+        data=np.zeros((5, 1, 2, 3)),  # epochs, channels, freqs, times
+        times=[0.1, 0.2, 0.3],
+        freqs=[0.1, 0.2],
+    )
+    tfr2 = EpochsTFRArray(
+        info=mne.create_info(["EEG 002", "EEG 003"], 1000, "eeg"),
+        data=np.zeros((5, 2, 2, 3)),  # epochs, channels, freqs, times
+        times=[0.1, 0.2, 0.3],
+        freqs=[0.1, 0.2],
+    )
+    tfr1.add_channels([tfr2])
+    assert tfr1.ch_names == ["EEG 001", "EEG 002", "EEG 003"]
+    assert tfr1.data.shape == (5, 3, 2, 3)
+
 
 def test_compute_tfr():
     """Test _compute_tfr function."""