BUG: Fix bug with compute_maxwell_basis(..., int_order=0) (mne-tools#11562)

Author: larsoner

doc/changes/latest.inc

@@ -54,6 +54,7 @@ Bugs
 - All functions accepting paths can now correctly handle :class:`~pathlib.Path` as input. Historically, we expected strings (instead of "proper" path objects), and only added :class:`~pathlib.Path` support in a few select places, leading to inconsistent behavior. (:gh:`11473` and :gh:`11499` by `Mathieu Scheltienne`_)
 - Fix visualization dialog compatibility with matplotlib 3.7 (:gh:`11409` by `Daniel McCloy`_ and `Eric Larson`_)
 - Expand tilde (user directory) in config keys (:gh:`11537` by `Clemens Brunner`_)
+- Fix bug in :func:`mne.preprocessing.compute_maxwell_basis` where using ``int_order=0`` would raise an error (:gh:`11562` by `Eric Larson`_)
 - Fix :func:`mne.io.read_raw` for file names containing multiple dots (:gh:`11521` by `Clemens Brunner`_)
 
 API changes

mne/preprocessing/maxwell.py

@@ -1978,18 +1978,24 @@ def _regularize_in(int_order, ext_order, S_decomp, mag_or_fine,
     # Pick the components that give at least 98% of max info
     # This is done because the curves can be quite flat, and we err on the
     # side of including rather than excluding components
-    max_info = np.max(I_tots)
-    lim_idx = np.where(I_tots >= 0.98 * max_info)[0][0]
-    in_removes = remove_order[:lim_idx]
-    for ii, ri in enumerate(in_removes):
-        logger.debug('            Condition %0.3f/%0.3f = %03.1f, '
-                     'Removing in component %s: l=%s, m=%+0.0f'
-                     % (tuple(eigs[ii]) + (eigs[ii, 0] / eigs[ii, 1],
-                                           ri, degrees[ri], orders[ri])))
-    logger.debug('        Resulting information: %0.1f bits/sample '
-                 '(%0.1f%% of peak %0.1f)'
-                 % (I_tots[lim_idx], 100 * I_tots[lim_idx] / max_info,
-                    max_info))
+    if n_in:
+        max_info = np.max(I_tots)
+        lim_idx = np.where(I_tots >= 0.98 * max_info)[0][0]
+        in_removes = remove_order[:lim_idx]
+        for ii, ri in enumerate(in_removes):
+            eig = eigs[ii]
+            logger.debug(
+                f'            Condition {eig[0]:0.3f} / {eig[1]:0.3f} = '
+                f'{eig[0] / eig[1]:03.1f}, Removing in component '
+                f'{ri}: l={degrees[ri]}, m={orders[ri]:+0.0f}'
+            )
+        logger.debug(
+            f'        Resulting information: {I_tots[lim_idx]:0.1f} '
+            f'bits/sample ({100 * I_tots[lim_idx] / max_info:0.1f}% of peak '
+            f'{max_info:0.1f})'
+        )
+    else:
+        in_removes = remove_order[:0]
     return in_removes, out_removes
 
 

mne/preprocessing/tests/test_maxwell.py

@@ -1438,19 +1438,21 @@ def test_find_bads_maxwell_flat():
     assert noisy == want_noisy
 
 
-@pytest.mark.parametrize('regularize, n', [
-    (None, 80),
-    ('in', 71),
+@pytest.mark.parametrize('regularize, n, int_order', [
+    (None, 80, 8),
+    ('in', 71, 8),
+    (None, 0, 0),
+    ('in', 0, 0),
 ])
-def test_compute_maxwell_basis(regularize, n):
+def test_compute_maxwell_basis(regularize, n, int_order):
     """Test compute_maxwell_basis."""
     raw = read_raw_fif(raw_small_fname).crop(0, 2)
     assert raw.info['bads'] == []
     raw.del_proj()
     rank = compute_rank(raw)['meg']
     assert rank == 306
     raw.info['bads'] = ['MEG 2443']
-    kwargs = dict(regularize=regularize, verbose=True)
+    kwargs = dict(regularize=regularize, int_order=int_order, verbose=True)
     raw_sss = maxwell_filter(raw, **kwargs)
     want = raw_sss.get_data('meg')
     rank = compute_rank(raw_sss)['meg']

mne/tests/test_import_nesting.py

@@ -5,6 +5,15 @@
 import sys
 from mne.utils import run_subprocess
 
+# To keep `import mne` time down, we nest most imports, including those of
+# required dependencies (e.g., pooch, tqdm, matplotlib). SciPy submodules
+# (esp. linalg) can take a while to load, so these imports must be nested, too.
+# NumPy is the exception -- it can be imported directly at the top of files.
+# N.B. that jinja2 is imported directly in mne/html_templates, so all imports
+# of mne.html_templates must be nested to achieve the jinja2 import being
+# nested during import of mne.
+#
+# This test ensures that we don't accidentally un-nest any of these imports.
 
 run_script = """
 import sys
@@ -13,8 +22,7 @@
 out = set()
 
 # check scipy (Numba imports it to check the version)
-ok_scipy_submodules = set(['scipy', 'numpy',  # these appear in old scipy
-                           'version'])
+ok_scipy_submodules = {'version'}
 scipy_submodules = set(x.split('.')[1] for x in sys.modules.keys()
                        if x.startswith('scipy.') and '__' not in x and
                        not x.split('.')[1].startswith('_')

requirements.txt

@@ -32,7 +32,7 @@ xlrd
 imageio>=2.6.1
 imageio-ffmpeg>=0.4.1
 traitlets
-pyvista>=0.32,!=0.35.2,!=0.38.0,!=0.38.1,!=0.38.2,!=0.38.3
+pyvista>=0.32,!=0.35.2,!=0.38.0,!=0.38.1,!=0.38.2,!=0.38.3,!=0.38.4
 pyvistaqt>=0.4
 mffpy>=0.5.7
 ipywidgets