第一。pyro 不支持 “ReduceLROnPlateau” ，因为需要Loss作为输入数值，计算量大
pytorch的学习率调整 视频 看这个博主的视频
第二 ，svi 支持 scheduler注意点，
属于 pyro.optim.PyroOptim的有三个 AdagradRMSProp ClippedAdam DCTAdam，但是还是会报错，类似下面的错误
optimizer = pyro.optim.SGD
# 指数下降学习率
pyro_scheduler = pyro.optim.ExponentialLR({'optimizer': optimizer, 'optim_args': {'lr': learn_rate}, 'gamma': 0.1})Traceback (most recent call last):
File "/home/aistudio/bnn_pyro_fso_middle_2_16__256.py", line 441, in <module>
svi = SVI(model, mean_field_guide, optimizer, loss=Trace_ELBO())
File "/home/aistudio/external-libraries/pyro/infer/svi.py", line 72, in __init__
raise ValueError(
ValueError: Optimizer should be an instance of pyro.optim.PyroOptim class.正确的方法是
optimizer = torch.optim.SGD
# 指数下降学习率
pyro_scheduler = pyro.optim.ExponentialLR({'optimizer': optimizer, 'optim_args': {'lr': learn_rate}, 'gamma': 0.1})
# 设置ReduceLROnPlateau调度器
# 在这个例子中，`'min'`模式表示当验证集上的损失停止下降时，学习率会降低。`factor=0.1`表示学习率会乘以0.1，`
# patience=10`表示如果验证集损失在连续10个epochs内没有改善，则降低学习率。
# scheduler = ReduceLROnPlateau(optimizer, 'min', factor=0.5, patience=20, verbose=True)
# svi = SVI(model, mean_field_guide, optimizer, loss=Trace_ELBO())
svi = SVI(model, mean_field_guide, pyro_scheduler, loss=Trace_ELBO())ExponentialLR
ExponentialLR是指数型下降的学习率调节器，每一轮会将学习率乘以gamma，所以这里千万注意gamma不要设置的太小，不然几轮之后学习率就会降到0。
lr_scheduler = lr_scheduler.ExponentialLR(optimizer, gamma=0.9)
# 按指数衰减调整学习率，调整公式：lr = lr*gamma**epoch
这是一个用于动态生成参数的调整学习率的包装器，用于 `torch.optim.lr_scheduler` 对象。
:param scheduler_constructor: 一个 `torch.optim.lr_scheduler` 的类
:param optim_args: 一个包含优化器学习参数的字典，或者是一个返回此类字典的可调用对象。必须包含键 'optimizer'，其值为 PyTorch 优化器的值
:param clip_args: 一个包含 `clip_norm` 和/或 `clip_value` 参数的字典，或者是一个返回此类字典的可调用对象。
例子::
optimizer = torch.optim.SGD
scheduler = pyro.optim.ExponentialLR({'optimizer': optimizer, 'optim_args': {'lr': 0.01}, 'gamma': 0.1})
svi = SVI(model, guide, scheduler, loss=TraceGraph_ELBO())
for i in range(epochs):
for minibatch in DataLoader(dataset, batch_size):
svi.step(minibatch)
scheduler.step()
"""
A wrapper for :class:`~torch.optim.lr_scheduler` objects that adjusts learning rates
for dynamically generated parameters.
:param scheduler_constructor: a :class:`~torch.optim.lr_scheduler`
:param optim_args: a dictionary of learning arguments for the optimizer or a callable that returns
such dictionaries. must contain the key 'optimizer' with pytorch optimizer value
:param clip_args: a dictionary of clip_norm and/or clip_value args or a callable that returns
such dictionaries.
Example::
optimizer = torch.optim.SGD
scheduler = pyro.optim.ExponentialLR({'optimizer': optimizer, 'optim_args': {'lr': 0.01}, 'gamma': 0.1})
svi = SVI(model, guide, scheduler, loss=TraceGraph_ELBO())
for i in range(epochs):
for minibatch in DataLoader(dataset, batch_size):
svi.step(minibatch)
scheduler.step()
pyro.optim.lr_scheduler的源代码
# Copyright (c) 2017-2019 Uber Technologies, Inc.
# SPDX-License-Identifier: Apache-2.0
from typing import Any, Dict, Iterable, List, Optional, Union, ValuesView
from torch import Tensor
from pyro.optim.optim import PyroOptim
class PyroLRScheduler(PyroOptim):
"""
A wrapper for :class:`~torch.optim.lr_scheduler` objects that adjusts learning rates
for dynamically generated parameters.
:param scheduler_constructor: a :class:`~torch.optim.lr_scheduler`
:param optim_args: a dictionary of learning arguments for the optimizer or a callable that returns
such dictionaries. must contain the key 'optimizer' with pytorch optimizer value
:param clip_args: a dictionary of clip_norm and/or clip_value args or a callable that returns
such dictionaries.
Example::
optimizer = torch.optim.SGD
scheduler = pyro.optim.ExponentialLR({'optimizer': optimizer, 'optim_args': {'lr': 0.01}, 'gamma': 0.1})
svi = SVI(model, guide, scheduler, loss=TraceGraph_ELBO())
for i in range(epochs):
for minibatch in DataLoader(dataset, batch_size):
svi.step(minibatch)
scheduler.step()
"""
def __init__(
self,
scheduler_constructor,
optim_args: Union[Dict],
clip_args: Optional[Union[Dict]] = None,
):
# pytorch scheduler
self.pt_scheduler_constructor = scheduler_constructor
# torch optimizer
pt_optim_constructor = optim_args.pop("optimizer")
# kwargs for the torch optimizer
optim_kwargs = optim_args.pop("optim_args")
self.kwargs = optim_args
super().__init__(pt_optim_constructor, optim_kwargs, clip_args)
def __call__(self, params: Union[List, ValuesView], *args, **kwargs) -> None:
super().__call__(params, *args, **kwargs)
def _get_optim(
self, params: Union[Tensor, Iterable[Tensor], Iterable[Dict[Any, Any]]]
):
optim = super()._get_optim(params)
return self.pt_scheduler_constructor(optim, **self.kwargs)
def step(self, *args, **kwargs) -> None:
"""
Takes the same arguments as the PyTorch scheduler
(e.g. optional ``loss`` for ``ReduceLROnPlateau``)
"""
for scheduler in self.optim_objs.values():
scheduler.step(*args, **kwargs)
