def load_data(datafile, maskfile=None):
""" load 4d nifti data """
if datafile.endswith("nii.gz") or datafile.endswith("nii"):
# we load the data this way rather than fileio.load() because we need
# access to the volumetric representation (to know the # coordinates)
dat = fileio.load_nifti(datafile, vol=True)
dim = dat.shape
if len(dim) <= 3:
dim = dim + (1, )
else:
raise ValueError("No routine to handle non-nifti data")
mask = fileio.create_mask(dat, mask=maskfile)
dat = fileio.vol2vec(dat, mask)
maskid = np.where(mask.ravel())[0]
# generate voxel coordinates
i, j, k = np.meshgrid(np.linspace(0, dim[0] - 1, dim[0]),
np.linspace(0, dim[1] - 1, dim[1]),
np.linspace(0, dim[2] - 1, dim[2]),
indexing='ij')
# voxel-to-world mapping
img = nib.load(datafile)
world = np.vstack(
(i.ravel(), j.ravel(), k.ravel(), np.ones(np.prod(i.shape), float))).T
world = np.dot(world, img.affine.T)[maskid, 0:3]
return dat, world, mask
def load_response_vars(datafile, maskfile=None, vol=True):
""" load response variables (of any data type)"""
if fileio.file_type(datafile) == 'nifti':
dat = fileio.load_nifti(datafile, vol=vol)
volmask = fileio.create_mask(dat, mask=maskfile)
Y = fileio.vol2vec(dat, volmask).T
else:
Y = fileio.load(datafile)
volmask = None
if fileio.file_type(datafile) == 'cifti':
Y = Y.T
return Y, volmask
def estimate(args):
torch.set_default_dtype(torch.float32)
args.type = 'MT'
print('Loading the input Data ...')
responses = fileio.load_nifti(args.respfile,
vol=True).transpose([3, 0, 1, 2])
response_shape = responses.shape
with open(args.covfile, 'rb') as handle:
covariates = pickle.load(handle)['covariates']
with open(args.testcovfile, 'rb') as handle:
test_covariates = pickle.load(handle)['test_covariates']
if args.mask is not None:
mask = fileio.load_nifti(args.mask, vol=True)
mask = fileio.create_mask(mask, mask=None)
else:
mask = fileio.create_mask(responses[0, :, :, :], mask=None)
if args.testrespfile is not None:
test_responses = fileio.load_nifti(args.testrespfile,
vol=True).transpose([3, 0, 1, 2])
test_responses_shape = test_responses.shape
print('Normalizing the input Data ...')
covariates_scaler = StandardScaler()
covariates = covariates_scaler.fit_transform(covariates)
test_covariates = covariates_scaler.transform(test_covariates)
response_scaler = MinMaxScaler()
responses = unravel_2D(response_scaler.fit_transform(ravel_2D(responses)),
response_shape)
if args.testrespfile is not None:
test_responses = unravel_2D(
response_scaler.transform(ravel_2D(test_responses)),
test_responses_shape)
test_responses = np.expand_dims(test_responses, axis=1)
factor = args.m
x_context = np.zeros([covariates.shape[0], factor, covariates.shape[1]],
dtype=np.float32)
y_context = np.zeros([
responses.shape[0], factor, responses.shape[1], responses.shape[2],
responses.shape[3]
],
dtype=np.float32)
x_all = np.zeros([covariates.shape[0], factor, covariates.shape[1]],
dtype=np.float32)
x_context_test = np.zeros(
[test_covariates.shape[0], factor, test_covariates.shape[1]],
dtype=np.float32)
y_context_test = np.zeros([
test_covariates.shape[0], factor, responses.shape[1],
responses.shape[2], responses.shape[3]
],
dtype=np.float32)
print('Estimating the fixed-effects ...')
for i in range(factor):
x_context[:, i, :] = covariates[:, :]
x_context_test[:, i, :] = test_covariates[:, :]
idx = np.random.randint(0, covariates.shape[0], covariates.shape[0])
if args.estimator == 'ST':
for j in range(responses.shape[1]):
for k in range(responses.shape[2]):
for l in range(responses.shape[3]):
reg = LinearRegression()
reg.fit(x_context[idx, i, :], responses[idx, j, k, l])
y_context[:, i, j, k, l] = reg.predict(x_context[:,
i, :])
y_context_test[:, i, j, k,
l] = reg.predict(x_context_test[:,
i, :])
elif args.estimator == 'MT':
reg = MultiTaskLasso(alpha=0.1)
reg.fit(
x_context[idx, i, :],
np.reshape(responses[idx, :, :, :],
[covariates.shape[0],
np.prod(responses.shape[1:])]))
y_context[:, i, :, :, :] = np.reshape(
reg.predict(x_context[:, i, :]), [
x_context.shape[0], responses.shape[1], responses.shape[2],
responses.shape[3]
])
y_context_test[:, i, :, :, :] = np.reshape(
reg.predict(x_context_test[:, i, :]), [
x_context_test.shape[0], responses.shape[1],
responses.shape[2], responses.shape[3]
])
print('Fixed-effect %d of %d is computed!' % (i + 1, factor))
x_all = x_context
responses = np.expand_dims(responses, axis=1).repeat(factor, axis=1)
################################## TRAINING #################################
encoder = Encoder(x_context, y_context, args).to(args.device)
args.cnn_feature_num = encoder.cnn_feature_num
decoder = Decoder(x_context, y_context, args).to(args.device)
model = NP(encoder, decoder, args).to(args.device)
print('Estimating the Random-effect ...')
k = 1
epochs = [
int(args.epochs / 4),
int(args.epochs / 2),
int(args.epochs / 5),
int(args.epochs - args.epochs / 4 - args.epochs / 2 - args.epochs / 5)
]
mini_batch_num = args.batchnum
batch_size = int(x_context.shape[0] / mini_batch_num)
model.train()
for e in range(len(epochs)):
optimizer = optim.Adam(model.parameters(), lr=10**(-e - 2))
for j in range(epochs[e]):
train_loss = 0
rand_idx = np.random.permutation(x_context.shape[0])
for i in range(mini_batch_num):
optimizer.zero_grad()
idx = rand_idx[i * batch_size:(i + 1) * batch_size]
y_hat, z_all, z_context, dummy = model(
torch.tensor(x_context[idx, :, :], device=args.device),
torch.tensor(y_context[idx, :, :, :, :],
device=args.device),
torch.tensor(x_all[idx, :, :], device=args.device),
torch.tensor(responses[idx, :, :, :, :],
device=args.device))
loss = np_loss(
y_hat,
torch.tensor(responses[idx, :, :, :, :],
device=args.device), z_all, z_context)
loss.backward()
train_loss += loss.item()
optimizer.step()
print('Epoch: %d, Loss:%f, Average Loss:%f' %
(k, train_loss, train_loss / responses.shape[0]))
k += 1
################################## Evaluation #################################
print('Predicting on Test Data ...')
model.eval()
model.apply(apply_dropout_test)
with torch.no_grad():
y_hat, z_all, z_context, y_sigma = model(
torch.tensor(x_context_test, device=args.device),
torch.tensor(y_context_test, device=args.device),
n=15)
if args.testrespfile is not None:
test_loss = np_loss(y_hat[0:test_responses_shape[0], :],
torch.tensor(test_responses, device=args.device),
z_all, z_context).item()
print('Average Test Loss:%f' % (test_loss / test_responses_shape[0]))
RMSE = np.sqrt(
np.mean((test_responses -
y_hat[0:test_responses_shape[0], :].cpu().numpy())**2,
axis=0)).squeeze() * mask
SMSE = RMSE**2 / np.var(test_responses, axis=0).squeeze()
Rho, pRho = compute_pearsonr(
test_responses.squeeze(),
y_hat[0:test_responses_shape[0], :].cpu().numpy().squeeze())
EXPV = explained_var(
test_responses.squeeze(),
y_hat[0:test_responses_shape[0], :].cpu().numpy().squeeze()) * mask
MSLL = compute_MSLL(
test_responses.squeeze(),
y_hat[0:test_responses_shape[0], :].cpu().numpy().squeeze(),
y_sigma[0:test_responses_shape[0], :].cpu().numpy().squeeze()**2,
train_mean=test_responses.mean(0),
train_var=test_responses.var(0)).squeeze() * mask
NPMs = (test_responses -
y_hat[0:test_responses_shape[0], :].cpu().numpy()) / (
y_sigma[0:test_responses_shape[0], :].cpu().numpy())
NPMs = NPMs.squeeze()
NPMs = NPMs * mask
NPMs = np.nan_to_num(NPMs)
temp = NPMs.reshape(
[NPMs.shape[0], NPMs.shape[1] * NPMs.shape[2] * NPMs.shape[3]])
EVD_params = extreme_value_prob_fit(temp, 0.01)
abnormal_probs = extreme_value_prob(EVD_params, temp, 0.01)
############################## SAVING RESULTS #################################
print('Saving Results to: %s' % (args.outdir))
exfile = args.respfile
y_hat = y_hat.squeeze().cpu().numpy()
y_hat = response_scaler.inverse_transform(ravel_2D(y_hat))
y_hat = y_hat[:, mask.flatten()]
fileio.save(y_hat.T,
args.outdir + '/yhat.nii.gz',
example=exfile,
mask=mask)
ys2 = y_sigma.squeeze().cpu().numpy()
ys2 = ravel_2D(ys2) * (response_scaler.data_max_ -
response_scaler.data_min_)
ys2 = ys2**2
ys2 = ys2[:, mask.flatten()]
fileio.save(ys2.T, args.outdir + '/ys2.nii.gz', example=exfile, mask=mask)
if args.testrespfile is not None:
NPMs = ravel_2D(NPMs)[:, mask.flatten()]
fileio.save(NPMs.T,
args.outdir + '/Z.nii.gz',
example=exfile,
mask=mask)
fileio.save(Rho.flatten()[mask.flatten()],
args.outdir + '/Rho.nii.gz',
example=exfile,
mask=mask)
fileio.save(pRho.flatten()[mask.flatten()],
args.outdir + '/pRho.nii.gz',
example=exfile,
mask=mask)
fileio.save(RMSE.flatten()[mask.flatten()],
args.outdir + '/rmse.nii.gz',
example=exfile,
mask=mask)
fileio.save(SMSE.flatten()[mask.flatten()],
args.outdir + '/smse.nii.gz',
example=exfile,
mask=mask)
fileio.save(EXPV.flatten()[mask.flatten()],
args.outdir + '/expv.nii.gz',
example=exfile,
mask=mask)
fileio.save(MSLL.flatten()[mask.flatten()],
args.outdir + '/msll.nii.gz',
example=exfile,
mask=mask)
with open(args.outdir + 'model.pkl', 'wb') as handle:
pickle.dump(
{
'model': model,
'covariates_scaler': covariates_scaler,
'response_scaler': response_scaler,
'EVD_params': EVD_params,
'abnormal_probs': abnormal_probs
},
handle,
protocol=pickle.HIGHEST_PROTOCOL)
###############################################################################
print('DONE!')