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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 Tensor s or int s or float s with strictly increasing entries, and with all elements having the same type as the optimizer step. |
values | A list of Tensor s or float s or int s 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 | if the number of elements in the lists do not match. |
from_config
@classmethod from_config( config )
Instantiates a LearningRateSchedule
from its config.
Args | |
---|---|
config | Output of get_config() . |
Returns | |
---|---|
A LearningRateSchedule instance. |
get_config
get_config()
__call__
__call__( step )
Call self as a function.
© 2020 The TensorFlow Authors. All rights reserved.
Licensed under the Creative Commons Attribution License 3.0.
Code samples licensed under the Apache 2.0 License.
https://www.tensorflow.org/versions/r2.4/api_docs/python/tf/keras/optimizers/schedules/PiecewiseConstantDecay