def compute_metrics(self, y_pred, y_true):
"""Compute metrics for predicted vs true labels."""
if not isinstance(y_pred, np.ndarray):
y_pred = array(y_pred)
if not isinstance(y_true, np.ndarray):
y_true = array(y_true)
if y_pred.ndim == 2:
y_pred = y_pred[:, -1]
y_true = y_true[:, -1]
metrics = {}
metrics['auroc'] = [roc_auc_score(y_true, y_pred)]
return metrics
def _valid_epoch(self, data_loader, storer=defaultdict(list)):
"""Trains the model on the validation set for one epoch."""
epoch_loss = 0.
y_preds = []
with trange(len(data_loader)) as t:
for data, y_true in data_loader:
data = data.to(self.device)
y_true = y_true.to(self.device)
y_pred = self.model(data)
y_preds += [array(y_pred)]
iter_loss = self.loss_f(y_pred, y_true, self.model.training,
storer)
epoch_loss += iter_loss.item()
if self.p_bar:
t.set_postfix(loss=iter_loss.item())
t.update()
y_preds = np.concatenate(y_preds)
y_trues = data_loader.dataset.Y
metrics = self.compute_metrics(y_preds, y_trues)
storer.update(metrics)
return epoch_loss / len(data_loader)
def predict(test_loader, model):
device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
model.eval()
preds = []
with torch.no_grad():
for X in test_loader:
X = X[0].to(device)
preds += [model(X)]
return array(torch.cat(preds))
def pmort_vs_time(model, idx, show_plot=True):
# Load data
data = np.load(os.path.join('data', 'arrs_48_20.npy')).item()
models = [f for f in os.listdir('results') if f.startswith(model)]
# Print info
print(idx, data['paths_train'][idx], data['Y_train'][idx])
preds = np.zeros((len(models), 48))
for i, model in enumerate(models):
# Load model
model_dir = os.path.join('results', model)
model = load_model(model_dir)
# Predict
device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
x = data['X_train'][idx:idx+1]
x = torch.tensor(x).to(device)
preds[i] = array(model(x))
# Bootstrap values
mu, lb, ub = bootstrap2d(preds, low=0.025, high=0.975, n_samples=10000)
# Plot
plt.fill_between(range(1, len(mu)+1), lb, ub, color='r', alpha=0.5, label='95% CI')
plt.plot(range(1, len(mu)+1), mu, ':ko', label='Mean')
plt.xlim(0, 48)
plt.xticks([0, 12, 24, 36, 48], fontsize=12)
plt.xlabel('In-Hospital Hours After Admission', fontsize=15)
plt.ylim(0, 1)
plt.yticks(np.linspace(0, 1, 11), fontsize=12)
plt.ylabel('p$_{mortality}$', fontsize=15)
plt.legend()
if show_plot:
plt.show()
else:
plt.savefig(os.path.join('figs', f'pmortvstime_48_20bins_idx{idx}.pdf'))
return array(x), model
def test(model, device, test_loader):
model.eval()
test_loss = 0
outputs = []
with torch.no_grad():
for data, target in test_loader:
data, target = data.to(device), target.to(device)
output = model(data)
test_loss += F.binary_cross_entropy(output, target).item()
outputs += [array(output)]
mean_test_loss = test_loss / len(test_loader)
outputs = np.concatenate(outputs)[:, -1]
targets = test_loader.dataset.Y[:, -1]
test_auroc = roc_auc_score(targets, outputs)
test_auprc = average_precision_score(targets, outputs)
return mean_test_loss, test_auroc, test_auprc
def case_study(model, idx):
case_study_dir = os.path.join('results', f'case_study_{idx}')
# Plot
x, model = pmort_vs_time(model, idx, show_plot=False)
# Reverse dict
token2index = np.load(os.path.join('data', 'token2index_48_20.npy')).item()
index2token = {v: k for k, v in token2index.items()}
index2token[0] = ''
# Hourly tokens and weights
weight = np.exp(array(model.embedder.embedW.weights)[:, 0])
token_inds = []
tokens = []
W = []
for t in np.arange(0, 48):
x_t = x[0, (t < x[0, :, 0]) & (x[0, :, 0] < (t + 1)), 1]
w = weight[x_t.astype(np.int64)]
inds = np.argsort(-w)
token_inds += [inds]
tokens += [np.array([index2token[i] for i in x_t])[inds]]
W += [w[inds]]
if not os.path.exists(case_study_dir):
os.makedirs(case_study_dir)
# Table
pd.DataFrame(token_inds).transpose().to_csv(os.path.join(
case_study_dir, 'input_inds.csv'),
index=None)
pd.DataFrame(tokens).transpose().to_csv(os.path.join(
case_study_dir, 'inputs.csv'),
index=None)
pd.DataFrame(W).transpose().to_csv(os.path.join(case_study_dir,
'weights.csv'),
index=None)
def _valid_epoch(self, data_loader_pos, data_loader_neg,
data_loader, storer=defaultdict(list)):
"""Trains the model on the validation set for one epoch."""
epoch_loss = 0.
coef_pos = 0.5
coef_neg = 0.5
y_preds_bal = []
y_trues_bal = []
y_preds_rand = []
y_trues_rand = []
loader_pos = iter(data_loader_pos)
loader_neg = iter(data_loader_neg)
with trange(len(data_loader)) as t:
for data, y_true in data_loader:
try:
X_pos, y_pos = next(loader_pos)
except StopIteration:
loader_pos = iter(data_loader_pos)
X_pos, y_pos = next(loader_pos)
try:
X_neg, y_neg = next(loader_neg)
except StopIteration:
loader_neg = iter(data_loader_neg)
X_neg, y_neg = next(loader_neg)
data = data.to(self.device)
y_true = y_true.to(self.device)
X_pos = X_pos.to(self.device)
y_pos = y_pos.to(self.device)
X_neg = X_neg.to(self.device)
y_neg = y_neg.to(self.device)
if_main = False
y_pred = self.model(data, if_main)
iter_loss_rand = self.loss_f(
y_pred, y_true, self.model.training, if_main, storer)
if_main = True
y_pred_pos = self.model(X_pos, if_main)
iter_loss_pos = self.loss_f(y_pred_pos, y_pos,
self.model.training, if_main, storer)
y_pred_neg = self.model(X_neg, if_main)
iter_loss_neg = self.loss_f(y_pred_neg, y_neg,
self.model.training, if_main, storer)
iter_loss_balance = iter_loss_pos * coef_pos + iter_loss_neg * coef_neg
iter_loss = (iter_loss_rand + iter_loss_balance) * 0.5
epoch_loss += iter_loss.item()
#y_preds += [array(y_pred)]
# only validate on balanced batch
y_trues_bal += [array(y_pos)]
y_trues_bal += [array(y_neg)]
y_preds_bal += [array(y_pred_pos)]
y_preds_bal += [array(y_pred_neg)]
y_trues_rand += [array(y_true)]
y_preds_rand += [array(y_pred)]
if self.p_bar:
t.set_postfix(loss=iter_loss.item())
t.update()
y_preds_bal = np.concatenate(y_preds_bal)
y_trues_bal = np.concatenate(y_trues_bal)
y_trues_rand = np.concatenate(y_trues_rand)
y_preds_rand = np.concatenate(y_preds_rand)
#y_trues = data_loader.dataset.Y
metrics = self.compute_metrics(y_preds_bal, y_trues_bal, if_bal=True)
storer.update(metrics)
metrics = self.compute_metrics(y_preds_rand, y_trues_rand, if_bal=False)
storer.update(metrics)
return epoch_loss / len(data_loader)
