TensorFlow 1 version | View source on GitHub |
Learning rate scheduler.
Inherits From: Callback
tf.keras.callbacks.LearningRateScheduler(
schedule, verbose=0
)
Used in the notebooks
Used in the tutorials |
---|
At the beginning of every epoch, this callback gets the updated learning rate
value from schedule
function provided at __init__
, with the current epoch
and current learning rate, and applies the updated learning rate
on the optimizer.
Arguments | |
---|---|
schedule
|
a function that takes an epoch index (integer, indexed from 0) and current learning rate (float) as inputs and returns a new learning rate as output (float). |
verbose
|
int. 0: quiet, 1: update messages. |
Example:
# This function keeps the initial learning rate for the first ten epochs
# and decreases it exponentially after that.
def scheduler(epoch, lr):
if epoch < 10:
return lr
else:
return lr * tf.math.exp(-0.1)
model = tf.keras.models.Sequential([tf.keras.layers.Dense(10)])
model.compile(tf.keras.optimizers.SGD(), loss='mse')
round(model.optimizer.lr.numpy(), 5)
0.01
callback = tf.keras.callbacks.LearningRateScheduler(scheduler)
history = model.fit(np.arange(100).reshape(5, 20), np.zeros(5),
epochs=15, callbacks=[callback], verbose=0)
round(model.optimizer.lr.numpy(), 5)
0.00607
Methods
set_model
set_model(
model
)
set_params
set_params(
params
)