# Combine the signals from the two conditions
signal = signal_A + signal_B
# Combine the stim functions
stimfunction = list(np.add(stimfunction_A, stimfunction_B))
stimfunction_tr = stimfunction[::int(tr_duration * temporal_res)]
# Generate the mask of the signal
mask, template = sim.mask_brain(signal, mask_threshold=0.2)
# Mask the signal to the shape of a brain (attenuates signal according to grey
# matter likelihood)
signal *= mask.reshape(dimensions[0], dimensions[1], dimensions[2], 1)
# Generate original noise dict for comparison later
orig_noise_dict = sim._noise_dict_update({})
# Create the noise volumes (using the default parameters
noise = sim.generate_noise(dimensions=dimensions,
stimfunction_tr=stimfunction_tr,
tr_duration=tr_duration,
mask=mask,
template=template,
noise_dict=orig_noise_dict,
)
# Standardize the signal activity to make it percent signal change
mean_act = (mask * orig_noise_dict['max_activity']).sum() / (mask > 0).sum()
signal = signal * mean_act / 100
# Combine the signal and the noise
def test_calc_noise():
# Inputs for functions
onsets = [10, 30, 50, 70, 90]
event_durations = [6]
tr_duration = 2
duration = 200
temporal_res = 100
tr_number = int(np.floor(duration / tr_duration))
dimensions_tr = np.array([10, 10, 10, tr_number])
# Preset the noise dict
nd_orig = sim._noise_dict_update({})
# Create the time course for the signal to be generated
stimfunction = sim.generate_stimfunction(
onsets=onsets,
event_durations=event_durations,
total_time=duration,
temporal_resolution=temporal_res,
)
# Mask the volume to be the same shape as a brain
mask, template = sim.mask_brain(dimensions_tr, mask_self=None)
stimfunction_tr = stimfunction[::int(tr_duration * temporal_res)]
nd_orig['matched'] = 0
noise = sim.generate_noise(
dimensions=dimensions_tr[0:3],
stimfunction_tr=stimfunction_tr,
tr_duration=tr_duration,
template=template,
mask=mask,
noise_dict=nd_orig,
)
# Check the spatial noise match
nd_orig['matched'] = 1
noise_matched = sim.generate_noise(dimensions=dimensions_tr[0:3],
stimfunction_tr=stimfunction_tr,
tr_duration=tr_duration,
template=template,
mask=mask,
noise_dict=nd_orig,
iterations=[50, 0])
# Calculate the noise parameters from this newly generated volume
nd_new = sim.calc_noise(noise, mask, template)
nd_matched = sim.calc_noise(noise_matched, mask, template)
# Check the values are reasonable"
assert nd_new['snr'] > 0, 'snr out of range'
assert nd_new['sfnr'] > 0, 'sfnr out of range'
assert nd_new['auto_reg_rho'][0] > 0, 'ar out of range'
# Check that the dilation increases SNR
no_dilation_snr = sim._calc_snr(
noise_matched,
mask,
dilation=0,
reference_tr=tr_duration,
)
assert nd_new['snr'] > no_dilation_snr, "Dilation did not increase SNR"
# Check that template size is in bounds
with pytest.raises(ValueError):
sim.calc_noise(noise, mask, template * 2)
# Check that Mask is set is checked
with pytest.raises(ValueError):
sim.calc_noise(noise, None, template)
# Check that it can deal with missing noise parameters
temp_nd = sim.calc_noise(noise, mask, template, noise_dict={})
assert temp_nd['voxel_size'][0] == 1, 'Default voxel size not set'
temp_nd = sim.calc_noise(noise, mask, template, noise_dict=None)
assert temp_nd['voxel_size'][0] == 1, 'Default voxel size not set'
# Check that the fitting worked
snr_diff = abs(nd_orig['snr'] - nd_new['snr'])
snr_diff_match = abs(nd_orig['snr'] - nd_matched['snr'])
assert snr_diff > snr_diff_match, 'snr fit incorrectly'
# Test that you can generate rician and exponential noise
sim._generate_noise_system(
dimensions_tr,
1,
1,
spatial_noise_type='exponential',
temporal_noise_type='rician',
)
# Check the temporal noise match
nd_orig['matched'] = 1
noise_matched = sim.generate_noise(dimensions=dimensions_tr[0:3],
stimfunction_tr=stimfunction_tr,
tr_duration=tr_duration,
template=template,
mask=mask,
noise_dict=nd_orig,
iterations=[0, 50])
nd_matched = sim.calc_noise(noise_matched, mask, template)
sfnr_diff = abs(nd_orig['sfnr'] - nd_new['sfnr'])
sfnr_diff_match = abs(nd_orig['sfnr'] - nd_matched['sfnr'])
assert sfnr_diff > sfnr_diff_match, 'sfnr fit incorrectly'
ar1_diff = abs(nd_orig['auto_reg_rho'][0] - nd_new['auto_reg_rho'][0])
ar1_diff_match = abs(nd_orig['auto_reg_rho'][0] -
nd_matched['auto_reg_rho'][0])
assert ar1_diff > ar1_diff_match, 'AR1 fit incorrectly'
# Check that you can calculate ARMA for a single voxel
vox = noise[5, 5, 5, :]
arma = sim._calc_ARMA_noise(
vox,
None,
sample_num=2,
)
assert len(arma) == 2, "Two outputs not given by ARMA"
def test_apply_signal():
dimensions = np.array([10, 10, 10]) # What is the size of the brain
feature_size = [2]
feature_type = ['cube']
feature_coordinates = np.array([[5, 5, 5]])
signal_magnitude = [30]
# Generate a volume representing the location and quality of the signal
volume = sim.generate_signal(
dimensions=dimensions,
feature_coordinates=feature_coordinates,
feature_type=feature_type,
feature_size=feature_size,
signal_magnitude=signal_magnitude,
)
# Inputs for generate_stimfunction
onsets = [10, 30, 50, 70, 90]
event_durations = [6]
tr_duration = 2
duration = 100
# Create the time course for the signal to be generated
stimfunction = sim.generate_stimfunction(
onsets=onsets,
event_durations=event_durations,
total_time=duration,
)
signal_function = sim.convolve_hrf(
stimfunction=stimfunction,
tr_duration=tr_duration,
)
# Check that you can compute signal change appropriately
# Preset a bunch of things
stimfunction_tr = stimfunction[::int(tr_duration * 100)]
mask, template = sim.mask_brain(dimensions, mask_self=False)
noise_dict = sim._noise_dict_update({})
noise = sim.generate_noise(dimensions=dimensions,
stimfunction_tr=stimfunction_tr,
tr_duration=tr_duration,
template=template,
mask=mask,
noise_dict=noise_dict,
iterations=[0, 0])
coords = feature_coordinates[0]
noise_function_a = noise[coords[0], coords[1], coords[2], :]
noise_function_a = noise_function_a.reshape(duration // tr_duration, 1)
noise_function_b = noise[coords[0] + 1, coords[1], coords[2], :]
noise_function_b = noise_function_b.reshape(duration // tr_duration, 1)
# Create the calibrated signal with PSC
method = 'PSC'
sig_a = sim.compute_signal_change(
signal_function,
noise_function_a,
noise_dict,
[0.5],
method,
)
sig_b = sim.compute_signal_change(
signal_function,
noise_function_a,
noise_dict,
[1.0],
method,
)
assert sig_b.max() / sig_a.max() == 2, 'PSC modulation failed'
# Create the calibrated signal with SFNR
method = 'SFNR'
sig_a = sim.compute_signal_change(
signal_function,
noise_function_a,
noise_dict,
[0.5],
method,
)
scaled_a = sig_a / (noise_function_a.mean() / noise_dict['sfnr'])
sig_b = sim.compute_signal_change(
signal_function,
noise_function_b,
noise_dict,
[1.0],
method,
)
scaled_b = sig_b / (noise_function_b.mean() / noise_dict['sfnr'])
assert scaled_b.max() / scaled_a.max() == 2, 'SFNR modulation failed'
# Create the calibrated signal with CNR_Amp/Noise-SD
method = 'CNR_Amp/Noise-SD'
sig_a = sim.compute_signal_change(
signal_function,
noise_function_a,
noise_dict,
[0.5],
method,
)
scaled_a = sig_a / noise_function_a.std()
sig_b = sim.compute_signal_change(
signal_function,
noise_function_b,
noise_dict,
[1.0],
method,
)
scaled_b = sig_b / noise_function_b.std()
assert scaled_b.max() / scaled_a.max() == 2, 'CNR_Amp modulation failed'
# Create the calibrated signal with CNR_Amp/Noise-Var_dB
method = 'CNR_Amp2/Noise-Var_dB'
sig_a = sim.compute_signal_change(
signal_function,
noise_function_a,
noise_dict,
[0.5],
method,
)
scaled_a = np.log(sig_a.max() / noise_function_a.std())
sig_b = sim.compute_signal_change(
signal_function,
noise_function_b,
noise_dict,
[1.0],
method,
)
scaled_b = np.log(sig_b.max() / noise_function_b.std())
assert np.round(scaled_b / scaled_a) == 2, 'CNR_Amp dB modulation failed'
# Create the calibrated signal with CNR_Signal-SD/Noise-SD
method = 'CNR_Signal-SD/Noise-SD'
sig_a = sim.compute_signal_change(
signal_function,
noise_function_a,
noise_dict,
[0.5],
method,
)
scaled_a = sig_a.std() / noise_function_a.std()
sig_b = sim.compute_signal_change(
signal_function,
noise_function_a,
noise_dict,
[1.0],
method,
)
scaled_b = sig_b.std() / noise_function_a.std()
assert (scaled_b / scaled_a) == 2, 'CNR signal modulation failed'
# Create the calibrated signal with CNR_Amp/Noise-Var_dB
method = 'CNR_Signal-Var/Noise-Var_dB'
sig_a = sim.compute_signal_change(
signal_function,
noise_function_a,
noise_dict,
[0.5],
method,
)
scaled_a = np.log(sig_a.std() / noise_function_a.std())
sig_b = sim.compute_signal_change(
signal_function,
noise_function_b,
noise_dict,
[1.0],
method,
)
scaled_b = np.log(sig_b.std() / noise_function_b.std())
assert np.round(scaled_b / scaled_a) == 2, 'CNR signal dB modulation ' \
'failed'
# Convolve the HRF with the stimulus sequence
signal = sim.apply_signal(
signal_function=signal_function,
volume_signal=volume,
)
assert signal.shape == (dimensions[0], dimensions[1], dimensions[2],
duration / tr_duration), "The output is the " \
"wrong size"
signal = sim.apply_signal(
signal_function=stimfunction,
volume_signal=volume,
)
assert np.any(signal == signal_magnitude), "The stimfunction is not binary"
# Check that there is an error if the number of signal voxels doesn't
# match the number of non zero brain voxels
with pytest.raises(IndexError):
sig_vox = (volume > 0).sum()
vox_pattern = np.tile(stimfunction, (1, sig_vox - 1))
sim.apply_signal(
signal_function=vox_pattern,
volume_signal=volume,
)
def test_calc_noise():
# Inputs for functions
onsets = [10, 30, 50, 70, 90]
event_durations = [6]
tr_duration = 2
duration = 200
temporal_res = 100
tr_number = int(np.floor(duration / tr_duration))
dimensions_tr = np.array([10, 10, 10, tr_number])
# Preset the noise dict
nd_orig = sim._noise_dict_update({})
# Create the time course for the signal to be generated
stimfunction = sim.generate_stimfunction(onsets=onsets,
event_durations=event_durations,
total_time=duration,
temporal_resolution=temporal_res,
)
# Mask the volume to be the same shape as a brain
mask, template = sim.mask_brain(dimensions_tr, mask_self=None)
stimfunction_tr = stimfunction[::int(tr_duration * temporal_res)]
nd_orig['matched'] = 0
noise = sim.generate_noise(dimensions=dimensions_tr[0:3],
stimfunction_tr=stimfunction_tr,
tr_duration=tr_duration,
template=template,
mask=mask,
noise_dict=nd_orig,
)
# Check the spatial noise match
nd_orig['matched'] = 1
noise_matched = sim.generate_noise(dimensions=dimensions_tr[0:3],
stimfunction_tr=stimfunction_tr,
tr_duration=tr_duration,
template=template,
mask=mask,
noise_dict=nd_orig,
iterations=[50, 0]
)
# Calculate the noise parameters from this newly generated volume
nd_new = sim.calc_noise(noise, mask, template)
nd_matched = sim.calc_noise(noise_matched, mask, template)
# Check the values are reasonable"
assert nd_new['snr'] > 0, 'snr out of range'
assert nd_new['sfnr'] > 0, 'sfnr out of range'
assert nd_new['auto_reg_rho'][0] > 0, 'ar out of range'
# Check that the dilation increases SNR
no_dilation_snr = sim._calc_snr(noise_matched,
mask,
dilation=0,
reference_tr=tr_duration,
)
assert nd_new['snr'] > no_dilation_snr, "Dilation did not increase SNR"
# Check that template size is in bounds
with pytest.raises(ValueError):
sim.calc_noise(noise, mask, template * 2)
# Check that Mask is set is checked
with pytest.raises(ValueError):
sim.calc_noise(noise, None, template)
# Check that it can deal with missing noise parameters
temp_nd = sim.calc_noise(noise, mask, template, noise_dict={})
assert temp_nd['voxel_size'][0] == 1, 'Default voxel size not set'
temp_nd = sim.calc_noise(noise, mask, template, noise_dict=None)
assert temp_nd['voxel_size'][0] == 1, 'Default voxel size not set'
# Check that the fitting worked
snr_diff = abs(nd_orig['snr'] - nd_new['snr'])
snr_diff_match = abs(nd_orig['snr'] - nd_matched['snr'])
assert snr_diff > snr_diff_match, 'snr fit incorrectly'
# Test that you can generate rician and exponential noise
sim._generate_noise_system(dimensions_tr,
1,
1,
spatial_noise_type='exponential',
temporal_noise_type='rician',
)
# Check the temporal noise match
nd_orig['matched'] = 1
noise_matched = sim.generate_noise(dimensions=dimensions_tr[0:3],
stimfunction_tr=stimfunction_tr,
tr_duration=tr_duration,
template=template,
mask=mask,
noise_dict=nd_orig,
iterations=[0, 50]
)
nd_matched = sim.calc_noise(noise_matched, mask, template)
sfnr_diff = abs(nd_orig['sfnr'] - nd_new['sfnr'])
sfnr_diff_match = abs(nd_orig['sfnr'] - nd_matched['sfnr'])
assert sfnr_diff > sfnr_diff_match, 'sfnr fit incorrectly'
ar1_diff = abs(nd_orig['auto_reg_rho'][0] - nd_new['auto_reg_rho'][0])
ar1_diff_match = abs(nd_orig['auto_reg_rho'][0] - nd_matched[
'auto_reg_rho'][0])
assert ar1_diff > ar1_diff_match, 'AR1 fit incorrectly'
# Check that you can calculate ARMA for a single voxel
vox = noise[5, 5, 5, :]
arma = sim._calc_ARMA_noise(vox,
None,
sample_num=2,
)
assert len(arma) == 2, "Two outputs not given by ARMA"
def test_apply_signal():
dimensions = np.array([10, 10, 10]) # What is the size of the brain
feature_size = [2]
feature_type = ['cube']
feature_coordinates = np.array(
[[5, 5, 5]])
signal_magnitude = [30]
# Generate a volume representing the location and quality of the signal
volume = sim.generate_signal(dimensions=dimensions,
feature_coordinates=feature_coordinates,
feature_type=feature_type,
feature_size=feature_size,
signal_magnitude=signal_magnitude,
)
# Inputs for generate_stimfunction
onsets = [10, 30, 50, 70, 90]
event_durations = [6]
tr_duration = 2
duration = 100
# Create the time course for the signal to be generated
stimfunction = sim.generate_stimfunction(onsets=onsets,
event_durations=event_durations,
total_time=duration,
)
signal_function = sim.convolve_hrf(stimfunction=stimfunction,
tr_duration=tr_duration,
)
# Check that you can compute signal change appropriately
# Preset a bunch of things
stimfunction_tr = stimfunction[::int(tr_duration * 100)]
mask, template = sim.mask_brain(dimensions, mask_self=False)
noise_dict = sim._noise_dict_update({})
noise = sim.generate_noise(dimensions=dimensions,
stimfunction_tr=stimfunction_tr,
tr_duration=tr_duration,
template=template,
mask=mask,
noise_dict=noise_dict,
iterations=[0, 0]
)
coords = feature_coordinates[0]
noise_function_a = noise[coords[0], coords[1], coords[2], :]
noise_function_a = noise_function_a.reshape(duration // tr_duration, 1)
noise_function_b = noise[coords[0] + 1, coords[1], coords[2], :]
noise_function_b = noise_function_b.reshape(duration // tr_duration, 1)
# Create the calibrated signal with PSC
method = 'PSC'
sig_a = sim.compute_signal_change(signal_function,
noise_function_a,
noise_dict,
[0.5],
method,
)
sig_b = sim.compute_signal_change(signal_function,
noise_function_a,
noise_dict,
[1.0],
method,
)
assert sig_b.max() / sig_a.max() == 2, 'PSC modulation failed'
# Create the calibrated signal with SFNR
method = 'SFNR'
sig_a = sim.compute_signal_change(signal_function,
noise_function_a,
noise_dict,
[0.5],
method,
)
scaled_a = sig_a / (noise_function_a.mean() / noise_dict['sfnr'])
sig_b = sim.compute_signal_change(signal_function,
noise_function_b,
noise_dict,
[1.0],
method,
)
scaled_b = sig_b / (noise_function_b.mean() / noise_dict['sfnr'])
assert scaled_b.max() / scaled_a.max() == 2, 'SFNR modulation failed'
# Create the calibrated signal with CNR_Amp/Noise-SD
method = 'CNR_Amp/Noise-SD'
sig_a = sim.compute_signal_change(signal_function,
noise_function_a,
noise_dict,
[0.5],
method,
)
scaled_a = sig_a / noise_function_a.std()
sig_b = sim.compute_signal_change(signal_function,
noise_function_b,
noise_dict,
[1.0],
method,
)
scaled_b = sig_b / noise_function_b.std()
assert scaled_b.max() / scaled_a.max() == 2, 'CNR_Amp modulation failed'
# Create the calibrated signal with CNR_Amp/Noise-Var_dB
method = 'CNR_Amp2/Noise-Var_dB'
sig_a = sim.compute_signal_change(signal_function,
noise_function_a,
noise_dict,
[0.5],
method,
)
scaled_a = np.log(sig_a.max() / noise_function_a.std())
sig_b = sim.compute_signal_change(signal_function,
noise_function_b,
noise_dict,
[1.0],
method,
)
scaled_b = np.log(sig_b.max() / noise_function_b.std())
assert np.round(scaled_b / scaled_a) == 2, 'CNR_Amp dB modulation failed'
# Create the calibrated signal with CNR_Signal-SD/Noise-SD
method = 'CNR_Signal-SD/Noise-SD'
sig_a = sim.compute_signal_change(signal_function,
noise_function_a,
noise_dict,
[0.5],
method,
)
scaled_a = sig_a.std() / noise_function_a.std()
sig_b = sim.compute_signal_change(signal_function,
noise_function_a,
noise_dict,
[1.0],
method,
)
scaled_b = sig_b.std() / noise_function_a.std()
assert (scaled_b / scaled_a) == 2, 'CNR signal modulation failed'
# Create the calibrated signal with CNR_Amp/Noise-Var_dB
method = 'CNR_Signal-Var/Noise-Var_dB'
sig_a = sim.compute_signal_change(signal_function,
noise_function_a,
noise_dict,
[0.5],
method,
)
scaled_a = np.log(sig_a.std() / noise_function_a.std())
sig_b = sim.compute_signal_change(signal_function,
noise_function_b,
noise_dict,
[1.0],
method,
)
scaled_b = np.log(sig_b.std() / noise_function_b.std())
assert np.round(scaled_b / scaled_a) == 2, 'CNR signal dB modulation ' \
'failed'
# Convolve the HRF with the stimulus sequence
signal = sim.apply_signal(signal_function=signal_function,
volume_signal=volume,
)
assert signal.shape == (dimensions[0], dimensions[1], dimensions[2],
duration / tr_duration), "The output is the " \
"wrong size"
signal = sim.apply_signal(signal_function=stimfunction,
volume_signal=volume,
)
assert np.any(signal == signal_magnitude), "The stimfunction is not binary"
# Check that there is an error if the number of signal voxels doesn't
# match the number of non zero brain voxels
with pytest.raises(IndexError):
sig_vox = (volume > 0).sum()
vox_pattern = np.tile(stimfunction, (1, sig_vox - 1))
sim.apply_signal(signal_function=vox_pattern,
volume_signal=volume,
)
# Combine the signals from the two conditions
signal = signal_A + signal_B
# Combine the stim functions
stimfunction = list(np.add(stimfunction_A, stimfunction_B))
stimfunction_tr = stimfunction[::int(tr_duration * temporal_res)]
# Generate the mask of the signal
mask = sim.mask_brain(signal)
# Mask the signal to the shape of a brain (attenuates signal according to grey
# matter likelihood)
signal *= mask
# Generate original noise dict for comparison later
orig_noise_dict = sim._noise_dict_update({})
# Create the noise volumes (using the default parameters
noise = sim.generate_noise(
dimensions=dimensions,
stimfunction_tr=stimfunction_tr,
tr_duration=tr_duration,
mask=mask,
noise_dict=orig_noise_dict,
)
# Standardize the signal activity to make it percent signal change
mean_act = (mask * orig_noise_dict['max_activity']).sum() / (mask > 0).sum()
signal = signal * mean_act / 100
# Combine the signal and the noise
