def test_read_dig_polhemus_isotrak_eeg(isotrak_eeg):
"""Test reading Polhemus IsoTrak EEG positions."""
N_CHANNELS = 5
_SEED = 42
EXPECTED_FID_IN_POLHEMUS = {
'nasion': np.array([1.1056e-01, -5.4210e-19, 0]),
'lpa': np.array([-2.1075e-04, 8.0793e-02, -7.5894e-19]),
'rpa': np.array([2.1075e-04, -8.0793e-02, -2.8731e-18]),
}
ch_names = ['eeg {:01d}'.format(ii) for ii in range(N_CHANNELS)]
EXPECTED_CH_POS = dict(zip(
ch_names, np.random.RandomState(_SEED).randn(N_CHANNELS, 3)))
montage = read_dig_polhemus_isotrak(fname=isotrak_eeg, ch_names=ch_names)
assert repr(montage) == (
'<DigMontage | '
'0 extras (headshape), 0 HPIs, 3 fiducials, 5 channels>'
)
fiducials, fid_coordframe = _get_fid_coords(montage.dig)
assert fid_coordframe == FIFF.FIFFV_COORD_UNKNOWN
for kk, val in fiducials.items():
assert_array_equal(val, EXPECTED_FID_IN_POLHEMUS[kk])
for kk, dig_point in zip(montage.ch_names, _get_dig_eeg(montage.dig)):
assert_array_equal(dig_point['r'], EXPECTED_CH_POS[kk])
assert dig_point['coord_frame'] == FIFF.FIFFV_COORD_UNKNOWN
def test_standard_montages_on_sphere(kind, tol, head_size):
"""Test some standard montage are on sphere."""
kwargs = dict()
if head_size != HEAD_SIZE_DEFAULT:
kwargs['head_size'] = head_size
montage = make_standard_montage(kind, **kwargs)
eeg_loc = np.array([ch['r'] for ch in _get_dig_eeg(montage.dig)])
assert_allclose(
actual=np.linalg.norm(eeg_loc, axis=1),
desired=np.full((eeg_loc.shape[0], ), head_size),
atol=tol,
)
def _get_dig_montage_pos(montage):
return np.array([d['r'] for d in _get_dig_eeg(montage.dig)])
