def rmse(y_true, y_pred):
m_factor = rmse_factor
m = RootMeanSquaredError()
m.update_state(inverse_transform(y_true, mmn),
inverse_transform(y_pred, mmn))
# return denormalize(m.result().numpy(), mmn) * m_factor
return m.result().numpy() * m_factor
def measure_rmse_tf(y_true, y_pred):
"""Calculate the RMSE score between y_true and y_pred and return it.
Parameters
----------
y_true : np.ndarray
Array of true values
y_pred : np.ndarray
Array of predicted values
Returns
-------
rmse : float
The RMSE between the arrays y_true and y_pred
"""
m = RootMeanSquaredError()
m.update_state(y_true, y_pred)
rmse = m.result().numpy()
return rmse
def measure_rmse_tf(y_true, y_pred):
m = RootMeanSquaredError()
m.update_state(y_true, y_pred)
result = m.result().numpy()
return result
def rmse(y_true, y_pred):
m_factor = rmse_factor
m = RootMeanSquaredError()
m.update_state(y_true, y_pred)
return denormalize(m.result().numpy(), mmn) * m_factor
def _training_loop(
self,
filepath: str,
train_gen: train_ts_generator, # can name of function be type?
val_gen: train_ts_generator,
epochs: int = 100,
steps_per_epoch: int = 50,
early_stopping: int = True,
stopping_patience: int = 5,
stopping_delta: int = 1,
) -> typing.Tuple[tf.Tensor, int]:
"""
util function
iterates over batches, updates gradients, records metrics, writes to tb, checkpoints, early stopping
"""
# set up metrics to track during training
batch_loss_avg = Mean()
epoch_loss_avg = Mean()
eval_loss_avg = Mean()
eval_mae = MeanAbsoluteError()
eval_rmse = RootMeanSquaredError()
# set up early stopping callback
early_stopping_cb = EarlyStopping(patience=stopping_patience,
active=early_stopping,
delta=stopping_delta)
# setup table for unscaling
self._lookup_table = build_tf_lookup(self._ts_obj.target_means)
# Iterate over epochs.
best_metric = math.inf
for epoch in range(epochs):
logger.info(f"Start of epoch {epoch}")
start_time = time.time()
for batch, (x_batch_train, cat_labels,
y_batch_train) in enumerate(train_gen):
# compute loss
with tf.GradientTape(persistent=True) as tape:
mu, scale = self._model(x_batch_train, training=True)
# softplus parameters
scale = softplus(scale)
if self._ts_obj.count_data:
mu = softplus(mu)
mu, scale = unscale(mu, scale, cat_labels,
self._lookup_table)
loss_value = self._loss_fn(y_batch_train, (mu, scale))
# sgd
if self._tb:
tf.summary.scalar("train_loss", loss_value,
epoch * steps_per_epoch + batch)
batch_loss_avg(loss_value)
epoch_loss_avg(loss_value)
grads = tape.gradient(loss_value,
self._model.trainable_weights)
self._optimizer.apply_gradients(
zip(grads, self._model.trainable_weights))
# Log 5x per epoch.
if batch % (steps_per_epoch // 5) == 0 and batch != 0:
logger.info(
f"Epoch {epoch}: Avg train loss over last {(steps_per_epoch // 5)} steps: {batch_loss_avg.result()}"
)
batch_loss_avg.reset_states()
# Run each epoch batches times
epoch_loss_avg_result = epoch_loss_avg.result()
if batch == steps_per_epoch:
logger.info(
f"Epoch {epoch} took {round(time.time() - start_time, 0)}s : Avg train loss: {epoch_loss_avg_result}"
)
break
# validation
if val_gen is not None:
logger.info(f"End of epoch {epoch}, validating...")
start_time = time.time()
for batch, (x_batch_val, cat_labels,
y_batch_val) in enumerate(val_gen):
# compute loss, doesn't need to be persistent bc not updating weights
with tf.GradientTape() as tape:
# treat as training -> reset lstm states inbetween each batch
mu, scale = self._model(x_batch_val, training=True)
# softplus parameters
mu, scale = self._softplus(mu, scale)
# unscale parameters
mu, scale = unscale(mu, scale, cat_labels,
self._lookup_table)
# calculate loss
loss_value = self._loss_fn(y_batch_val, (mu, scale))
# log validation metrics (avg loss, avg MAE, avg RMSE)
eval_mae(y_batch_val, mu)
eval_rmse(y_batch_val, mu)
eval_loss_avg(loss_value)
if batch == steps_per_epoch:
break
# logging
eval_mae_result = eval_mae.result()
logger.info(
f"Validation took {round(time.time() - start_time, 0)}s")
logger.info(
f"Epoch {epoch}: Val loss on {steps_per_epoch} steps: {eval_loss_avg.result()}"
)
logger.info(
f"Epoch {epoch}: Val MAE: {eval_mae_result}, RMSE: {eval_rmse.result()}"
)
if self._tb:
tf.summary.scalar("val_loss", eval_loss_avg.result(),
epoch)
tf.summary.scalar("val_mae", eval_mae_result, epoch)
tf.summary.scalar("val_rmse", eval_rmse.result(), epoch)
new_metric = eval_mae_result
# early stopping
if early_stopping_cb(eval_mae_result):
break
# reset metric states
eval_loss_avg.reset_states()
eval_mae.reset_states()
eval_rmse.reset_states()
else:
if early_stopping_cb(epoch_loss_avg_result):
break
new_metric = epoch_loss_avg_result
# update best_metric and save new checkpoint if improvement
if new_metric < best_metric:
best_metric = new_metric
if filepath is not None:
self._checkpointer.save(file_prefix=filepath)
else:
self.save_weights("model_best_weights.h5")
# reset epoch loss metric
epoch_loss_avg.reset_states()
# load in best weights before returning if not using checkpointer
if filepath is None:
self.load_weights("model_best_weights.h5")
os.remove("model_best_weights.h5")
return best_metric, epoch + 1
