# -*- coding: utf-8 -*-
__author__ = "Ngoc Huynh Bao"
__email__ = "ngoc.huynh.bao@nmbu.no"
from ..keras.optimizers import Optimizer, deserialize
from ..utils import Singleton
[docs]class Optimizers(metaclass=Singleton):
"""
A singleton that contains all the registered customized optimizers
"""
def __init__(self):
self._optimizers = {}
[docs] def register(self, key, optimizer):
if not issubclass(optimizer, Optimizer):
raise ValueError(
"The customized optimizer has to be a subclass"
+ " of keras.optimizers.Optimizer"
)
if key in self._optimizers:
raise KeyError(
"Duplicated key, please use another key for this optimizer"
)
else:
self._optimizers[key] = optimizer
[docs] def unregister(self, key):
if key in self._optimizers:
del self._optimizers[key]
@property
def optimizers(self):
return self._optimizers
[docs]def register_optimizer(key, optimizer):
"""
Register the customized optimizer.
If the key name is already registered, it will raise a KeyError exception
Parameters
----------
key : str
The unique key-name of the optimizer
optimizer : tensorflow.keras.optimizers.Optimizer
The customized optimizer class
"""
Optimizers().register(key, optimizer)
[docs]def unregister_optimizer(key):
"""
Remove the registered optimizer with the key-name
Parameters
----------
key : str
The key-name of the optimizer to be removed
"""
Optimizers().unregister(key)
[docs]def optimizer_from_config(config):
if 'class_name' not in config:
raise ValueError('class_name is needed to define optimizer')
if 'config' not in config:
# auto add empty config for optimizer with only class_name
config['config'] = {}
return deserialize(config, custom_objects=Optimizers().optimizers)