Extensions

make_shift

chainercv.chainer_experimental.training.extensions.make_shift(attr, optimizer=None)

Decorator to make shift extensions.

This decorator wraps a function and makes a shift extension. Base function should take trainer and return a new value of attr.

Here is an example.

>>> # define an extension that updates 'lr' attribute
>>> @make_shift('lr')
>>> def warmup(trainer):
>>>     base_lr = 0.01
>>>     rate = 0.1
>>>
>>>     iteration = trainer.updater.iteration
>>>     if iteration < 1000:
>>>         return base_lr * (rate + (1 - rate) * iteraion / 1000)
>>>     else:
>>>         return base_lr
>>>
>>> # use the extension
>>> trainer.extend(warmup)

Parameters

• attr (str) – Name of the attribute to shift.

• optimizer (Optimizer) – Target optimizer to adjust the attribute. If it is None, the main optimizer of the updater is used.