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TensorFlow 1 version
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View source on GitHub
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A LearningRateSchedule that uses a piecewise constant decay schedule.
Inherits From: LearningRateSchedule
tf.keras.optimizers.schedules.PiecewiseConstantDecay(
boundaries, values, name=None
)
The function returns a 1-arg callable to compute the piecewise constant when passed the current optimizer step. This can be useful for changing the learning rate value across different invocations of optimizer functions.
Example: use a learning rate that's 1.0 for the first 100001 steps, 0.5 for the next 10000 steps, and 0.1 for any additional steps.
step = tf.Variable(0, trainable=False)
boundaries = [100000, 110000]
values = [1.0, 0.5, 0.1]
learning_rate_fn = keras.optimizers.schedules.PiecewiseConstantDecay(
boundaries, values)
# Later, whenever we perform an optimization step, we pass in the step.
learning_rate = learning_rate_fn(step)
You can pass this schedule directly into a tf.keras.optimizers.Optimizer
as the learning rate. The learning rate schedule is also serializable and
deserializable using tf.keras.optimizers.schedules.serialize and
tf.keras.optimizers.schedules.deserialize.
Returns | |
|---|---|
A 1-arg callable learning rate schedule that takes the current optimizer
step and outputs the decayed learning rate, a scalar Tensor of the same
type as the boundary tensors.
The output of the 1-arg function that takes the |
Args | |
|---|---|
boundaries
|
A list of Tensors or ints or floats with strictly
increasing entries, and with all elements having the same type as the
optimizer step.
|
values
|
A list of Tensors or floats or ints that specifies the
values for the intervals defined by boundaries. It should have one
more element than boundaries, and all elements should have the same
type.
|
name
|
A string. Optional name of the operation. Defaults to 'PiecewiseConstant'. |
Raises | |
|---|---|
ValueError
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if the number of elements in the lists do not match. |
Methods
from_config
@classmethodfrom_config( config )
Instantiates a LearningRateSchedule from its config.
| Args | |
|---|---|
config
|
Output of get_config().
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| Returns | |
|---|---|
A LearningRateSchedule instance.
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get_config
get_config()
__call__
__call__(
step
)
Call self as a function.