File: test_interpolate.py

package info (click to toggle)
python-mne 1.3.0%2Bdfsg-1
  • links: PTS, VCS
  • area: main
  • in suites: bookworm
  • size: 100,172 kB
  • sloc: python: 166,349; pascal: 3,602; javascript: 1,472; sh: 334; makefile: 236
file content (184 lines) | stat: -rw-r--r-- 7,454 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
import itertools
import os.path as op

import numpy as np
import pytest

from mne import create_info, io, pick_types, read_events, Epochs
from mne.channels import make_standard_montage
from mne.preprocessing import equalize_bads, interpolate_bridged_electrodes
from mne.preprocessing.interpolate import _find_centroid_sphere
from mne.transforms import _cart_to_sph

base_dir = op.join(op.dirname(__file__), '..', '..', 'io', 'tests', 'data')
raw_fname = op.join(base_dir, 'test_raw.fif')
event_name = op.join(base_dir, 'test-eve.fif')
raw_fname_ctf = op.join(base_dir, 'test_ctf_raw.fif')

event_id, tmin, tmax = 1, -0.2, 0.5
event_id_2 = 2


def _load_data():
    """Load data."""
    # It is more memory efficient to load data in a separate
    # function so it's loaded on-demand
    raw = io.read_raw_fif(raw_fname).pick(['eeg', 'stim'])
    events = read_events(event_name)
    # subselect channels for speed
    picks = pick_types(raw.info, meg=False, eeg=True, exclude=[])[:15]
    epochs = Epochs(raw, events, event_id, tmin, tmax, picks=picks,
                    preload=True, reject=dict(eeg=80e-6))
    evoked = epochs.average()
    return raw.load_data(), epochs.load_data(), evoked


@pytest.mark.parametrize('interp_thresh', [0., 0.5, 1.])
@pytest.mark.parametrize('inst_type', ['raw', 'epochs', 'evoked'])
def test_equalize_bads(interp_thresh, inst_type):
    """Test equalize_bads function."""
    raw, epochs, evoked = _load_data()

    if inst_type == 'raw':
        insts = [raw.copy().crop(0, 1), raw.copy().crop(0, 2)]
    elif inst_type == 'epochs':
        insts = [epochs.copy()[:1], epochs.copy()[:2]]
    else:
        insts = [evoked.copy().crop(0, 0.1), raw.copy().crop(0, 0.2)]

    with pytest.raises(ValueError, match='between 0'):
        equalize_bads(insts, interp_thresh=2.)

    bads = insts[0].copy().pick('eeg').ch_names[:3]
    insts[0].info['bads'] = bads[:2]
    insts[1].info['bads'] = bads[1:]

    insts_ok = equalize_bads(insts, interp_thresh=interp_thresh)
    if interp_thresh == 0:
        bads_ok = []
    elif interp_thresh == 1:
        bads_ok = bads
    else:  # interp_thresh == 0.5
        bads_ok = bads[1:]

    for inst in insts_ok:
        assert set(inst.info['bads']) == set(bads_ok)


def test_interpolate_bridged_electrodes():
    """Test interpolate_bridged_electrodes function."""
    raw, epochs, evoked = _load_data()
    for inst in (raw, epochs, evoked):
        idx0 = inst.ch_names.index('EEG 001')
        idx1 = inst.ch_names.index('EEG 002')
        ch_names_orig = inst.ch_names.copy()
        bads_orig = inst.info['bads'].copy()
        inst2 = inst.copy()
        inst2.info['bads'] = ['EEG 001', 'EEG 002']
        inst2.interpolate_bads()
        data_interp_reg = inst2.get_data(picks=['EEG 001', 'EEG 002'])
        inst = interpolate_bridged_electrodes(inst, [(idx0, idx1)])
        data_interp = inst.get_data(picks=['EEG 001', 'EEG 002'])
        assert not any(['virtual' in ch for ch in inst.ch_names])
        assert inst.ch_names == ch_names_orig
        assert inst.info['bads'] == bads_orig
        # check closer to regular interpolation than original data
        assert 1e-6 < np.mean(np.abs(data_interp - data_interp_reg)) < 5.4e-5

    for inst in (raw, epochs, evoked):
        idx0 = inst.ch_names.index('EEG 001')
        idx1 = inst.ch_names.index('EEG 002')
        idx2 = inst.ch_names.index('EEG 003')
        ch_names_orig = inst.ch_names.copy()
        bads_orig = inst.info['bads'].copy()
        inst2 = inst.copy()
        inst2.info['bads'] = ['EEG 001', 'EEG 002', 'EEG 003']
        inst2.interpolate_bads()
        data_interp_reg = inst2.get_data(
            picks=['EEG 001', 'EEG 002', 'EEG 003']
        )
        inst = interpolate_bridged_electrodes(
            inst, [(idx0, idx1), (idx0, idx2), (idx1, idx2)]
        )
        data_interp = inst.get_data(picks=['EEG 001', 'EEG 002', 'EEG 003'])
        assert not any(['virtual' in ch for ch in inst.ch_names])
        assert inst.ch_names == ch_names_orig
        assert inst.info['bads'] == bads_orig
        # check closer to regular interpolation than original data
        assert 1e-6 < np.mean(np.abs(data_interp - data_interp_reg)) < 5.4e-5

    # test bad_limit
    montage = make_standard_montage("standard_1020")
    ch_names = [ch for ch in montage.ch_names
                if ch not in ["P7", "P8", "T3", "T4", "T5", "T4", "T6"]]
    info = create_info(ch_names, sfreq=1024, ch_types="eeg")
    data = np.random.randn(len(ch_names), 1024)
    data[:5, :] = np.ones((5, 1024))
    raw = io.RawArray(data, info)
    raw.set_montage("standard_1020")
    bridged_idx = list(itertools.combinations(range(5), 2))
    with pytest.raises(
        RuntimeError,
        match="The channels Fp1, Fpz, Fp2, AF9, AF7 are bridged "
        "together and form a large area of bridged electrodes."
    ):
        interpolate_bridged_electrodes(raw, bridged_idx, bad_limit=4)
    # increase the limit to prevent raising
    interpolate_bridged_electrodes(raw, bridged_idx, bad_limit=5)
    # invalid argument
    with pytest.raises(
        ValueError,
        match="Argument 'bad_limit' should be a strictly positive integer."
    ):
        interpolate_bridged_electrodes(raw, bridged_idx, bad_limit=-4)


def test_find_centroid():
    """Test that the centroid is correct."""
    montage = make_standard_montage("standard_1020")
    ch_names = [ch for ch in montage.ch_names
                if ch not in ["P7", "P8", "T3", "T4", "T5", "T4", "T6"]]
    info = create_info(ch_names, sfreq=1024, ch_types="eeg")
    info.set_montage(montage)
    montage = info.get_montage()
    pos = montage.get_positions()
    assert pos["coord_frame"] == "head"

    # look for centroid between T7 and TP7, an average in spehrical coordinate
    # fails and places the average on the wrong side of the head between T8 and
    # TP8
    ch_names = ["T7", "TP7"]
    pos_centroid = _find_centroid_sphere(pos["ch_pos"], ch_names)
    _check_centroid_position(pos, ch_names, pos_centroid)

    # check other positions
    pairs = [("CPz", "CP2"), ("CPz", "Cz"), ("Fpz", "AFz"), ("AF7", "F7"),
             ("O1", "O2"), ("M2", "A2"), ("P5", "P9")]
    for ch_names in pairs:
        pos_centroid = _find_centroid_sphere(pos["ch_pos"], ch_names)
        _check_centroid_position(pos, ch_names, pos_centroid)
    triplets = [("CPz", "Cz", "FCz"), ("AF9", "Fpz", "AF10"),
                ("FT10", "FT8", "T10")]
    for ch_names in triplets:
        pos_centroid = _find_centroid_sphere(pos["ch_pos"], ch_names)
        _check_centroid_position(pos, ch_names, pos_centroid)


def _check_centroid_position(pos, ch_names, pos_centroid):
    """Check the centroid distance.

    The cartesian average should be distanced from pos_centroid by the
    difference between the radii.
    """
    radii = list()
    cartesian_positions = np.zeros((len(ch_names), 3))
    for i, ch in enumerate(ch_names):
        radii.append(_cart_to_sph(pos["ch_pos"][ch])[0, 0])
        cartesian_positions[i, :] = pos["ch_pos"][ch]
    avg_radius = np.average(radii)
    avg_cartesian_position = np.average(cartesian_positions, axis=0)
    avg_cartesian_position_radius = _cart_to_sph(avg_cartesian_position)[0, 0]
    radius_diff = np.abs(avg_radius - avg_cartesian_position_radius)
    # distance
    distance = np.linalg.norm(pos_centroid - avg_cartesian_position)
    assert np.isclose(radius_diff, distance, atol=1e-6)