Applies cosine decay with restarts to the learning rate.
tf.train.cosine_decay_restarts( learning_rate, global_step, first_decay_steps, t_mul=2.0, m_mul=1.0, alpha=0.0, name=None )
See [Loshchilov & Hutter, ICLR2016], SGDR: Stochastic Gradient Descent with Warm Restarts. https://arxiv.org/abs/1608.03983
When training a model, it is often recommended to lower the learning rate as
the training progresses. This function applies a cosine decay function with
restarts to a provided initial learning rate. It requires a
value to compute the decayed learning rate. You can just pass a TensorFlow
variable that you increment at each training step.
The function returns the decayed learning rate while taking into account
possible warm restarts. The learning rate multiplier first decays
from 1 to
first_decay_steps steps. Then, a warm
restart is performed. Each new warm restart runs for
t_mul times more steps
m_mul times smaller initial learning rate.
first_decay_steps = 1000 lr_decayed = cosine_decay_restarts(learning_rate, global_step, first_decay_steps)
learning_rate: A scalar
float64Tensor or a Python number. The initial learning rate.
global_step: A scalar
Tensoror a Python number. Global step to use for the decay computation.
first_decay_steps: A scalar
Tensoror a Python number. Number of steps to decay over.
t_mul: A scalar
Tensoror a Python number. Used to derive the number of iterations in the i-th period
m_mul: A scalar
Tensoror a Python number. Used to derive the initial learning rate of the i-th period:
alpha: A scalar
float64Tensor or a Python number. Minimum learning rate value as a fraction of the learning_rate.
name: String. Optional name of the operation. Defaults to 'SGDRDecay'.
Tensor of the same type as
learning_rate. The decayed
global_stepis not supplied.
When eager execution is enabled, this function returns a function which in turn returns the decayed learning rate Tensor. This can be useful for changing the learning rate value across different invocations of optimizer functions.