text
stringlengths 0
4.99k
|
---|
batch: A test batch containing the keys \"source\" and \"target\"
|
idx_to_token: A List containing the vocabulary tokens corresponding to their indices
|
target_start_token_idx: A start token index in the target vocabulary
|
target_end_token_idx: An end token index in the target vocabulary
|
\"\"\"
|
self.batch = batch
|
self.target_start_token_idx = target_start_token_idx
|
self.target_end_token_idx = target_end_token_idx
|
self.idx_to_char = idx_to_token
|
def on_epoch_end(self, epoch, logs=None):
|
if epoch % 5 != 0:
|
return
|
source = self.batch[\"source\"]
|
target = self.batch[\"target\"].numpy()
|
bs = tf.shape(source)[0]
|
preds = self.model.generate(source, self.target_start_token_idx)
|
preds = preds.numpy()
|
for i in range(bs):
|
target_text = \"\".join([self.idx_to_char[_] for _ in target[i, :]])
|
prediction = \"\"
|
for idx in preds[i, :]:
|
prediction += self.idx_to_char[idx]
|
if idx == self.target_end_token_idx:
|
break
|
print(f\"target: {target_text.replace('-','')}\")
|
print(f\"prediction: {prediction}\n\")
|
Learning rate schedule
|
class CustomSchedule(keras.optimizers.schedules.LearningRateSchedule):
|
def __init__(
|
self,
|
init_lr=0.00001,
|
lr_after_warmup=0.001,
|
final_lr=0.00001,
|
warmup_epochs=15,
|
decay_epochs=85,
|
steps_per_epoch=203,
|
):
|
super().__init__()
|
self.init_lr = init_lr
|
self.lr_after_warmup = lr_after_warmup
|
self.final_lr = final_lr
|
self.warmup_epochs = warmup_epochs
|
self.decay_epochs = decay_epochs
|
self.steps_per_epoch = steps_per_epoch
|
def calculate_lr(self, epoch):
|
\"\"\" linear warm up - linear decay \"\"\"
|
warmup_lr = (
|
self.init_lr
|
+ ((self.lr_after_warmup - self.init_lr) / (self.warmup_epochs - 1)) * epoch
|
)
|
decay_lr = tf.math.maximum(
|
self.final_lr,
|
self.lr_after_warmup
|
- (epoch - self.warmup_epochs)
|
* (self.lr_after_warmup - self.final_lr)
|
/ (self.decay_epochs),
|
)
|
return tf.math.minimum(warmup_lr, decay_lr)
|
def __call__(self, step):
|
epoch = step // self.steps_per_epoch
|
return self.calculate_lr(epoch)
|
Create & train the end-to-end model
|
batch = next(iter(val_ds))
|
# The vocabulary to convert predicted indices into characters
|
idx_to_char = vectorizer.get_vocabulary()
|
display_cb = DisplayOutputs(
|
batch, idx_to_char, target_start_token_idx=2, target_end_token_idx=3
|
) # set the arguments as per vocabulary index for '<' and '>'
|
model = Transformer(
|
num_hid=200,
|
num_head=2,
|
num_feed_forward=400,
|
target_maxlen=max_target_len,
|
num_layers_enc=4,
|
num_layers_dec=1,
|
num_classes=34,
|
)
|
loss_fn = tf.keras.losses.CategoricalCrossentropy(
|
from_logits=True, label_smoothing=0.1,
|
)
|
learning_rate = CustomSchedule(
|
init_lr=0.00001,
|
lr_after_warmup=0.001,
|
final_lr=0.00001,
|
warmup_epochs=15,
|
decay_epochs=85,
|
steps_per_epoch=len(ds),
|
)
|
optimizer = keras.optimizers.Adam(learning_rate)
|
model.compile(optimizer=optimizer, loss=loss_fn)
|
history = model.fit(ds, validation_data=val_ds, callbacks=[display_cb], epochs=1)
|
203/203 [==============================] - 349s 2s/step - loss: 1.7437 - val_loss: 1.4650
|
target: <he had neither a bed to lie upon nor a coat to his back.>
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.