
Learn2Learn是用于元学习研究的软件库。
Learn2Learn在Pytorch之上建立,以加速元学习研究周期的两个方面:
Learn2Learn提供了低级实用程序和统一的界面,以创建新的算法和域,以及现有算法和标准化基准的高质量实现。它保留了与Torchvision,Torchaudio,Torchtext,Cherry和您可能使用的任何其他基于Pytorch的库的兼容性。
要了解更多信息,请参阅我们的白皮书:Arxiv:2008.12284
概述
learn2learn.data : Taskset和转换以从任何Pytorch数据集创建几个弹药任务。learn2learn.vision :用于计算机视觉和少量学习的模型,数据集和基准。learn2learn.gym :元提升学习的环境和实用程序。learn2learn.algorithms :现有元学习算法的高级包装器。learn2learn.optim :用于可区分优化和元偏发现的实用程序和算法。资源
pip install learn2learn以下片段可窥视学习2learn的功能。
有关更多算法(质子,Anil,Meta-SGD,Reptile,Meta-Curvature,kfo),请参阅示例文件夹。它们中的大多数可以与GBML包装器一起实施。 (文档)。
maml = l2l . algorithms . MAML ( model , lr = 0.1 )
opt = torch . optim . SGD ( maml . parameters (), lr = 0.001 )
for iteration in range ( 10 ):
opt . zero_grad ()
task_model = maml . clone () # torch.clone() for nn.Modules
adaptation_loss = compute_loss ( task_model )
task_model . adapt ( adaptation_loss ) # computes gradient, update task_model in-place
evaluation_loss = compute_loss ( task_model )
evaluation_loss . backward () # gradients w.r.t. maml.parameters()
opt . step ()通过LearnableOptimizer学习任何形式的优化算法。 (例如和文档)
linear = nn . Linear ( 784 , 10 )
transform = l2l . optim . ModuleTransform ( l2l . nn . Scale )
metaopt = l2l . optim . LearnableOptimizer ( linear , transform , lr = 0.01 ) # metaopt has .step()
opt = torch . optim . SGD ( metaopt . parameters (), lr = 0.001 ) # metaopt also has .parameters()
metaopt . zero_grad ()
opt . zero_grad ()
error = loss ( linear ( X ), y )
error . backward ()
opt . step () # update metaopt
metaopt . step () # update linear许多标准化数据集(Omniglot,Mini-/tiered-Imagenet,FC100,CIFAR-FS)很容易在learn2learn.vision.datasets中获得。 (文档)
dataset = l2l . data . MetaDataset ( MyDataset ()) # any PyTorch dataset
transforms = [ # Easy to define your own transform
l2l . data . transforms . NWays ( dataset , n = 5 ),
l2l . data . transforms . KShots ( dataset , k = 1 ),
l2l . data . transforms . LoadData ( dataset ),
]
taskset = Taskset ( dataset , transforms , num_tasks = 20000 )
for task in taskset :
X , y = task
# Meta-train on the task与AsyncVectorEnv或使用标准化的环境并行化您自己的元环境。 (文档)
def make_env ():
env = l2l . gym . HalfCheetahForwardBackwardEnv ()
env = cherry . envs . ActionSpaceScaler ( env )
return env
env = l2l . gym . AsyncVectorEnv ([ make_env for _ in range ( 16 )]) # uses 16 threads
for task_config in env . sample_tasks ( 20 ):
env . set_task ( task ) # all threads receive the same task
state = env . reset () # use standard Gym API
action = my_policy ( env )
env . step ( action )通过更新Pytorch模块来学习和区分。 (文档)
model = MyModel ()
transform = l2l . optim . KroneckerTransform ( l2l . nn . KroneckerLinear )
learned_update = l2l . optim . ParameterUpdate ( # learnable update function
model . parameters (), transform )
clone = l2l . clone_module ( model ) # torch.clone() for nn.Modules
error = loss ( clone ( X ), y )
updates = learned_update ( # similar API as torch.autograd.grad
error ,
clone . parameters (),
create_graph = True ,
)
l2l . update_module ( clone , updates = updates )
loss ( clone ( X ), y ). backward () # Gradients w.r.t model.parameters() and learned_update.parameters() changelog.md文件中可用人为可读的变形值。
为了在您的学术出版物中引用learn2learn存储库,请使用以下参考。
Arnold,Sebastien MR,Praateek Mahajan,Debajyoti Datta,Ian Bunner和Konstantinos Saitas Zarkias。 2020年。“ Learn2learn:元学习研究的库。” arxiv [cs.lg]。 http://arxiv.org/abs/2008.12284。
您也可以使用以下Bibtex条目。
@article { Arnold2020-ss ,
title = " learn2learn: A Library for {Meta-Learning} Research " ,
author = " Arnold, S{'e}bastien M R and Mahajan, Praateek and Datta,
Debajyoti and Bunner, Ian and Zarkias, Konstantinos Saitas " ,
month = aug,
year = 2020 ,
url = " http://arxiv.org/abs/2008.12284 " ,
archivePrefix = " arXiv " ,
primaryClass = " cs.LG " ,
eprint = " 2008.12284 "
}
nn.Module有关更多信息,请参阅其Arxiv论文。