def test_bad_by_hf_noise(raw_tmp):
"""Test detection of channels with high-frequency noise."""
# Add some noise between 70 & 80 Hz to the signal of a random channel
n_chans = raw_tmp._data.shape[0]
hf_noise_idx = int(RNG.randint(0, n_chans, 1))
hf_noise = _generate_signal(70, 80, raw_tmp.times, 5) * 10
raw_tmp._data[hf_noise_idx, :] += hf_noise
# Test detection of channels with high-frequency noise
nd = NoisyChannels(raw_tmp, do_detrend=False)
nd.find_bad_by_hfnoise()
assert nd.bad_by_hf_noise == [raw_tmp.ch_names[hf_noise_idx]]
# Test lack of high-frequency noise detection when sample rate < 100 Hz
raw_tmp.resample(80) # downsample from 160 Hz to 80 Hz
nd = NoisyChannels(raw_tmp, do_detrend=False)
nd.find_bad_by_hfnoise()
assert len(nd.bad_by_hf_noise) == 0
assert nd._extra_info["bad_by_hf_noise"]["median_channel_noisiness"] == 0
assert nd._extra_info["bad_by_hf_noise"]["channel_noisiness_sd"] == 1
def test_findnoisychannels(raw, montage):
raw.set_montage(montage)
nd = NoisyChannels(raw)
nd.find_all_bads(ransac=True)
bads = nd.get_bads()
iterations = (
10 # remove any noisy channels by interpolating the bads for 10 iterations
)
for iter in range(0, iterations):
raw.info["bads"] = bads
raw.interpolate_bads()
nd = NoisyChannels(raw)
nd.find_all_bads(ransac=True)
bads = nd.get_bads()
# make sure no bad channels exist in the data
raw.drop_channels(ch_names=bads)
# Test for NaN and flat channels
raw_tmp = raw.copy()
m, n = raw_tmp._data.shape
# Insert a nan value for a random channel
rand_chn_idx1 = int(np.random.randint(0, m, 1))
rand_chn_idx2 = int(np.random.randint(0, m, 1))
rand_chn_lab1 = raw_tmp.ch_names[rand_chn_idx1]
rand_chn_lab2 = raw_tmp.ch_names[rand_chn_idx2]
raw_tmp._data[rand_chn_idx1, n - 1] = np.nan
raw_tmp._data[rand_chn_idx2, :] = np.ones(n)
nd = NoisyChannels(raw_tmp)
nd.find_bad_by_nan_flat()
assert nd.bad_by_nan == [rand_chn_lab1]
assert nd.bad_by_flat == [rand_chn_lab2]
# Test for high and low deviations in EEG data
raw_tmp = raw.copy()
m, n = raw_tmp._data.shape
# Now insert one random channel with very low deviations
rand_chn_idx = int(np.random.randint(0, m, 1))
rand_chn_lab = raw_tmp.ch_names[rand_chn_idx]
raw_tmp._data[rand_chn_idx, :] = raw_tmp._data[rand_chn_idx, :] / 10
nd = NoisyChannels(raw_tmp)
nd.find_bad_by_deviation()
assert rand_chn_lab in nd.bad_by_deviation
# Inserting one random channel with a high deviation
raw_tmp = raw.copy()
rand_chn_idx = int(np.random.randint(0, m, 1))
rand_chn_lab = raw_tmp.ch_names[rand_chn_idx]
arbitrary_scaling = 5
raw_tmp._data[rand_chn_idx, :] *= arbitrary_scaling
nd = NoisyChannels(raw_tmp)
nd.find_bad_by_deviation()
assert rand_chn_lab in nd.bad_by_deviation
# Test for correlation between EEG channels
raw_tmp = raw.copy()
m, n = raw_tmp._data.shape
rand_chn_idx = int(np.random.randint(0, m, 1))
rand_chn_lab = raw_tmp.ch_names[rand_chn_idx]
# Use cosine instead of sine to create a signal
low = 10
high = 30
n_freq = 5
signal = np.zeros((1, n))
for freq_i in range(n_freq):
freq = np.random.randint(low, high, n)
signal[0, :] += np.cos(2 * np.pi * raw.times * freq)
raw_tmp._data[rand_chn_idx, :] = signal * 1e-6
nd = NoisyChannels(raw_tmp)
nd.find_bad_by_correlation()
assert rand_chn_lab in nd.bad_by_correlation
# Test for high freq noise detection
raw_tmp = raw.copy()
m, n = raw_tmp._data.shape
rand_chn_idx = int(np.random.randint(0, m, 1))
rand_chn_lab = raw_tmp.ch_names[rand_chn_idx]
# Use freqs between 90 and 100 Hz to insert hf noise
signal = np.zeros((1, n))
for freq_i in range(n_freq):
freq = np.random.randint(90, 100, n)
signal[0, :] += np.sin(2 * np.pi * raw.times * freq)
raw_tmp._data[rand_chn_idx, :] = signal * 1e-6
nd = NoisyChannels(raw_tmp)
nd.find_bad_by_hfnoise()
assert rand_chn_lab in nd.bad_by_hf_noise
# Test for signal to noise ratio in EEG data
raw_tmp = raw.copy()
m, n = raw_tmp._data.shape
rand_chn_idx = int(np.random.randint(0, m, 1))
rand_chn_lab = raw_tmp.ch_names[rand_chn_idx]
# inserting an uncorrelated high frequency (90 Hz) signal in one channel
raw_tmp[rand_chn_idx, :] = np.sin(2 * np.pi * raw.times * 90) * 1e-6
nd = NoisyChannels(raw_tmp)
nd.find_bad_by_SNR()
assert rand_chn_lab in nd.bad_by_SNR
# Test for finding bad channels by RANSAC
raw_tmp = raw.copy()
# Ransac identifies channels that go bad together and are highly correlated.
# Inserting highly correlated signal in channels 0 through 3 at 30 Hz
raw_tmp._data[0:6, :] = np.cos(2 * np.pi * raw.times * 30) * 1e-6
nd = NoisyChannels(raw_tmp)
np.random.seed(30)
nd.find_bad_by_ransac()
bads = nd.bad_by_ransac
assert bads == raw_tmp.ch_names[0:6]
def test_findnoisychannels(raw, montage):
"""Test find noisy channels."""
# Set a random state for the test
rng = np.random.RandomState(30)
raw.set_montage(montage)
nd = NoisyChannels(raw, random_state=rng)
nd.find_all_bads(ransac=True)
bads = nd.get_bads()
iterations = (
10 # remove any noisy channels by interpolating the bads for 10 iterations
)
for iter in range(0, iterations):
if len(bads) == 0:
continue
raw.info["bads"] = bads
raw.interpolate_bads()
nd = NoisyChannels(raw, random_state=rng)
nd.find_all_bads(ransac=True)
bads = nd.get_bads()
# make sure no bad channels exist in the data
raw.drop_channels(ch_names=bads)
# Test for NaN and flat channels
raw_tmp = raw.copy()
m, n = raw_tmp._data.shape
# Insert a nan value for a random channel and make another random channel
# completely flat (ones)
idxs = rng.choice(np.arange(m), size=2, replace=False)
rand_chn_idx1 = idxs[0]
rand_chn_idx2 = idxs[1]
rand_chn_lab1 = raw_tmp.ch_names[rand_chn_idx1]
rand_chn_lab2 = raw_tmp.ch_names[rand_chn_idx2]
raw_tmp._data[rand_chn_idx1, n - 1] = np.nan
raw_tmp._data[rand_chn_idx2, :] = np.ones(n)
nd = NoisyChannels(raw_tmp, random_state=rng)
nd.find_bad_by_nan_flat()
assert nd.bad_by_nan == [rand_chn_lab1]
assert nd.bad_by_flat == [rand_chn_lab2]
# Test for high and low deviations in EEG data
raw_tmp = raw.copy()
m, n = raw_tmp._data.shape
# Now insert one random channel with very low deviations
rand_chn_idx = int(rng.randint(0, m, 1))
rand_chn_lab = raw_tmp.ch_names[rand_chn_idx]
raw_tmp._data[rand_chn_idx, :] = raw_tmp._data[rand_chn_idx, :] / 10
nd = NoisyChannels(raw_tmp, random_state=rng)
nd.find_bad_by_deviation()
assert rand_chn_lab in nd.bad_by_deviation
# Inserting one random channel with a high deviation
raw_tmp = raw.copy()
rand_chn_idx = int(rng.randint(0, m, 1))
rand_chn_lab = raw_tmp.ch_names[rand_chn_idx]
arbitrary_scaling = 5
raw_tmp._data[rand_chn_idx, :] *= arbitrary_scaling
nd = NoisyChannels(raw_tmp, random_state=rng)
nd.find_bad_by_deviation()
assert rand_chn_lab in nd.bad_by_deviation
# Test for correlation between EEG channels
raw_tmp = raw.copy()
m, n = raw_tmp._data.shape
rand_chn_idx = int(rng.randint(0, m, 1))
rand_chn_lab = raw_tmp.ch_names[rand_chn_idx]
# Use cosine instead of sine to create a signal
low = 10
high = 30
n_freq = 5
signal = np.zeros((1, n))
for freq_i in range(n_freq):
freq = rng.randint(low, high, n)
signal[0, :] += np.cos(2 * np.pi * raw.times * freq)
raw_tmp._data[rand_chn_idx, :] = signal * 1e-6
nd = NoisyChannels(raw_tmp, random_state=rng)
nd.find_bad_by_correlation()
assert rand_chn_lab in nd.bad_by_correlation
# Test for high freq noise detection
raw_tmp = raw.copy()
m, n = raw_tmp._data.shape
rand_chn_idx = int(rng.randint(0, m, 1))
rand_chn_lab = raw_tmp.ch_names[rand_chn_idx]
# Use freqs between 90 and 100 Hz to insert hf noise
signal = np.zeros((1, n))
for freq_i in range(n_freq):
freq = rng.randint(90, 100, n)
signal[0, :] += np.sin(2 * np.pi * raw.times * freq)
raw_tmp._data[rand_chn_idx, :] = signal * 1e-6
nd = NoisyChannels(raw_tmp, random_state=rng)
nd.find_bad_by_hfnoise()
assert rand_chn_lab in nd.bad_by_hf_noise
# Test for signal to noise ratio in EEG data
raw_tmp = raw.copy()
m, n = raw_tmp._data.shape
rand_chn_idx = int(rng.randint(0, m, 1))
rand_chn_lab = raw_tmp.ch_names[rand_chn_idx]
# inserting an uncorrelated high frequency (90 Hz) signal in one channel
raw_tmp[rand_chn_idx, :] = np.sin(2 * np.pi * raw.times * 90) * 1e-6
nd = NoisyChannels(raw_tmp, random_state=rng)
nd.find_bad_by_SNR()
assert rand_chn_lab in nd.bad_by_SNR
# Test for finding bad channels by RANSAC
raw_tmp = raw.copy()
# Ransac identifies channels that go bad together and are highly correlated.
# Inserting highly correlated signal in channels 0 through 3 at 30 Hz
raw_tmp._data[0:6, :] = np.cos(2 * np.pi * raw.times * 30) * 1e-6
nd = NoisyChannels(raw_tmp, random_state=rng)
nd.find_bad_by_ransac()
bads = nd.bad_by_ransac
assert bads == raw_tmp.ch_names[0:6]
# Test for finding bad channels by channel-wise RANSAC
raw_tmp = raw.copy()
# Ransac identifies channels that go bad together and are highly correlated.
# Inserting highly correlated signal in channels 0 through 3 at 30 Hz
raw_tmp._data[0:6, :] = np.cos(2 * np.pi * raw.times * 30) * 1e-6
nd = NoisyChannels(raw_tmp, random_state=rng)
nd.find_bad_by_ransac(channel_wise=True)
bads = nd.bad_by_ransac
assert bads == raw_tmp.ch_names[0:6]
# Test not-enough-memory and n_samples type exceptions
raw_tmp = raw.copy()
raw_tmp._data[0:6, :] = np.cos(2 * np.pi * raw.times * 30) * 1e-6
nd = NoisyChannels(raw_tmp, random_state=rng)
# Set n_samples very very high to trigger a memory error
n_samples = int(1e100)
with pytest.raises(MemoryError):
nd.find_bad_by_ransac(n_samples=n_samples)
# Set n_samples to a float to trigger a type error
n_samples = 35.5
with pytest.raises(TypeError):
nd.find_bad_by_ransac(n_samples=n_samples)
# Test IOError when not enough channels for ransac predictions
raw_tmp = raw.copy()
# Make flat all channels except 2
num_bad_channels = raw._data.shape[0] - 2
raw_tmp._data[0:num_bad_channels, :] = np.zeros_like(
raw_tmp._data[0:num_bad_channels, :]
)
nd = NoisyChannels(raw_tmp, random_state=rng)
nd.find_all_bads(ransac=False)
with pytest.raises(IOError):
nd.find_bad_by_ransac()