Fix a bug for ica.get_sources() and add a corresponding test (mne-tools#13068)

Author: BeiGeJin

doc/changes/dev/13068.bugfix.rst

@@ -0,0 +1 @@
+Fixed ICA getting sources for concatenated raw instances, by :newcontrib:`Beige Jin`.

doc/changes/names.inc

@@ -33,6 +33,7 @@
 .. _Ashley Drew: https://github.com/ashdrew
 .. _Asish Panda: https://github.com/kaichogami
 .. _Austin Hurst: https://github.com/a-hurst
+.. _Beige Jin: https://github.com/BeiGeJin
 .. _Ben Beasley: https://github.com/musicinmybrain
 .. _Bradley Voytek: https://github.com/voytek
 .. _Britta Westner: https://britta-wstnr.github.io

mne/preprocessing/ica.py

@@ -1295,8 +1295,10 @@ def _sources_as_raw(self, raw, add_channels, start, stop):
             picks = pick_channels(raw.ch_names, add_channels)
             data_ = np.concatenate([data_, raw.get_data(picks, start=start, stop=stop)])
         out._data = data_
-        out._first_samps = [out.first_samp]
-        out._last_samps = [out.last_samp]
+        out_first_samp = out.first_samp
+        out_last_samp = out.last_samp
+        out._first_samps = [out_first_samp]
+        out._last_samps = [out_last_samp]
         out.filenames = [None]
         out.preload = True
         out._projector = None

mne/preprocessing/tests/test_ica.py

@@ -25,6 +25,7 @@
     EpochsArray,
     EvokedArray,
     Info,
+    concatenate_raws,
     create_info,
     make_ad_hoc_cov,
     pick_channels_regexp,
@@ -1727,3 +1728,21 @@ def test_ica_ch_types(ch_type):
     for inst in [raw, epochs, evoked]:
         ica.apply(inst)
         ica.get_sources(inst)
+
+
+@testing.requires_testing_data
+def test_ica_get_sources_concatenated():
+    """Test ICA get_sources method with concatenated raws."""
+    # load data
+    raw = read_raw_fif(raw_fname).crop(0, 3).load_data()  # raw has 3 seconds of data
+    # create concatenated raw instances
+    raw_concat = concatenate_raws(
+        [raw.copy(), raw.copy()]
+    )  # raw_concat has 6 seconds of data
+    # do ICA
+    ica = ICA(n_components=2, max_iter=2)
+    with _record_warnings(), pytest.warns(UserWarning, match="did not converge"):
+        ica.fit(raw_concat)
+    # get sources
+    raw_sources = ica.get_sources(raw_concat)  # but this only has 3 seconds of data
+    assert raw_concat.n_times == raw_sources.n_times  # this will fail