exponential_decay¶

paddle.static. exponential_decay ( learning_rate, decay_steps, decay_rate, staircase=False ) [source]

Applies exponential decay to the learning rate.

When training a model, it is often recommended to lower the learning rate as the training progresses. By using this function, the learning rate will be decayed by ‘decay_rate’ every ‘decay_steps’ steps.

Decayed learning rate calculates as follows:

>>> if staircase == True:
>>>     decayed_learning_rate = learning_rate * decay_rate ^ floor(global_step / decay_steps)
>>> else:
>>>     decayed_learning_rate = learning_rate * decay_rate ^ (global_step / decay_steps)

Parameters

• learning_rate (Variable|float) – The initial learning rate. It should be a Variable or a float

• decay_steps (int) – The learning rate decay steps. See the decay computation above.

• decay_rate (float) – The learning rate decay rate. See the decay computation above.

• staircase (bool) – If True, decay the learning rate at discrete intervals, which means the learning rate will be decayed by decay_rate every decay_steps. If False, learning rate will be decayed continuously and following the formula above. Default: False

Returns

The decayed learning rate. The data type is float32.

Return type

Variable

Examples

import paddle.fluid as fluid
import paddle

paddle.enable_static()
base_lr = 0.1
sgd_optimizer = fluid.optimizer.SGD(
    learning_rate=fluid.layers.exponential_decay(
          learning_rate=base_lr,
          decay_steps=10000,
          decay_rate=0.5,
          staircase=True))