def test_calc_noise():
# Inputs for functions
onsets = [10, 30, 50, 70, 90]
event_durations = [6]
tr_duration = 2
duration = 200
tr_number = int(np.floor(duration / tr_duration))
dimensions_tr = np.array([10, 10, 10, tr_number])
# Preset the noise dict
nd_orig = {
'auto_reg_sigma': 0.6,
'drift_sigma': 0.4,
'snr': 30,
'sfnr': 30,
'max_activity': 1000,
'fwhm': 4,
}
# Create the time course for the signal to be generated
stimfunction = sim.generate_stimfunction(
onsets=onsets,
event_durations=event_durations,
total_time=duration,
)
# Mask the volume to be the same shape as a brain
mask, template = sim.mask_brain(dimensions_tr, mask_threshold=0.2)
stimfunction_tr = stimfunction[::int(tr_duration * 100)]
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 that noise_system is being calculated correctly
spatial_sd = 5
temporal_sd = 5
noise_system = sim._generate_noise_system(dimensions_tr, spatial_sd,
temporal_sd)
precision = abs(noise_system[0, 0, 0, :].std() - spatial_sd)
assert precision < spatial_sd, 'noise_system calculated incorrectly'
precision = abs(noise_system[:, :, :, 0].std() - temporal_sd)
assert precision < spatial_sd, 'noise_system calculated incorrectly'
# Calculate the noise
nd_calc = sim.calc_noise(volume=noise, mask=mask)
# How precise are these estimates
precision = abs(nd_calc['snr'] - nd_orig['snr'])
assert precision < nd_orig['snr'], 'snr calculated incorrectly'
precision = abs(nd_calc['sfnr'] - nd_orig['sfnr'])
assert precision < nd_orig['sfnr'], 'sfnr calculated incorrectly'
def test_calc_noise():
# Inputs for functions
onsets = [10, 30, 50, 70, 90]
event_durations = [6]
tr_duration = 2
duration = 200
tr_number = int(np.floor(duration / tr_duration))
dimensions_tr = np.array([10, 10, 10, tr_number])
# Preset the noise dict
nd_orig = {'auto_reg_sigma': 0.6,
'drift_sigma': 0.4,
'snr': 30,
'sfnr': 30,
'max_activity': 1000,
'fwhm': 4,
}
# Create the time course for the signal to be generated
stimfunction = sim.generate_stimfunction(onsets=onsets,
event_durations=event_durations,
total_time=duration,
)
# Mask the volume to be the same shape as a brain
mask, template = sim.mask_brain(dimensions_tr, mask_threshold=0.2)
stimfunction_tr = stimfunction[::int(tr_duration * 100)]
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 that noise_system is being calculated correctly
spatial_sd = 5
temporal_sd = 5
noise_system = sim._generate_noise_system(dimensions_tr,
spatial_sd,
temporal_sd)
precision = abs(noise_system[0, 0, 0, :].std() - spatial_sd)
assert precision < spatial_sd, 'noise_system calculated incorrectly'
precision = abs(noise_system[:, :, :, 0].std() - temporal_sd)
assert precision < spatial_sd, 'noise_system calculated incorrectly'
# Calculate the noise
nd_calc = sim.calc_noise(volume=noise,
mask=mask)
# How precise are these estimates
precision = abs(nd_calc['snr'] - nd_orig['snr'])
assert precision < nd_orig['snr'], 'snr calculated incorrectly'
precision = abs(nd_calc['sfnr'] - nd_orig['sfnr'])
assert precision < nd_orig['sfnr'], 'sfnr calculated incorrectly'
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_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"