def drop_path(x, drop_prob: float = 0., training: bool = False, scale_by_keep: bool = True): """Drop paths (Stochastic Depth) per sample (when applied in main path of residual blocks). This is the same as the DropConnect impl I created for EfficientNet, etc networks, however, the original name is misleading as 'Drop Connect' is a different form of dropout in a separate paper... See discussion: https://github.com/tensorflow/tpu/issues/494#issuecomment-532968956 ... I've opted for changing the layer and argument names to 'drop path' rather than mix DropConnect as a layer name and use 'survival rate' as the argument. """ if drop_prob == 0. or not training: return x keep_prob = 1 - drop_prob shape = (x.shape[0],) + (1,) * (x.ndim - 1) # work with diff dim tensors, not just 2D ConvNets random_tensor = x.new_empty(shape).bernoulli_(keep_prob) if keep_prob > 0.0 and scale_by_keep: random_tensor.div_(keep_prob) return x * random_tensor
时间: 2024-04-10 16:29:03 浏览: 150
这段代码是一个用于实现Stochastic Depth(随机深度)的函数。Stochastic Depth是一种在残差网络主路径中应用的路径丢弃技术。
函数的输入参数包括:
- `x`:输入张量。
- `drop_prob`:丢弃概率,用于控制丢弃的路径比例。
- `training`:是否处于训练模式,用于控制是否应用路径丢弃。
- `scale_by_keep`:是否根据保留概率进行缩放。
函数的返回值是经过路径丢弃处理后的张量。
具体实现中,首先判断`drop_prob`是否为0或者是否处于非训练模式,如果是,则直接返回输入张量`x`,不进行路径丢弃操作。
然后,计算保留概率`keep_prob`,即1减去丢弃概率`drop_prob`。
接着,根据输入张量`x`的形状创建一个与其相同形状的随机张量`random_tensor`,其中的元素服从伯努利分布,并且取值为1的概率为保留概率`keep_prob`。
如果保留概率大于0且`scale_by_keep`为True,则对随机张量进行缩放,将其除以保留概率`keep_prob`。
最后,将输入张量`x`与随机张量`random_tensor`相乘,得到经过路径丢弃处理后的张量,并返回。
总的来说,这段代码实现了Stochastic Depth中的路径丢弃操作,可以根据丢弃概率在训练过程中随机丢弃一部分路径,从而增强模型的鲁棒性和泛化能力。
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def drop_path(x, drop_prob: float = 0., training: bool = False): """Drop paths (Stochastic Depth) per sample (when applied in main path of residual blocks). This is the same as the DropConnect impl I created for EfficientNet, etc networks, however, the original name is misleading as 'Drop Connect' is a different form of dropout in a separate paper... See discussion: https://github.com/tensorflow/tpu/issues/494#issuecomment-532968956 ... I've opted for changing the layer and argument names to 'drop path' rather than mix DropConnect as a layer name and use 'survival rate' as the argument. """ if drop_prob == 0. or not training: return x keep_prob = 1 - drop_prob shape = (x.shape[0],) + (1,) * (x.ndim - 1) # work with diff dim tensors, not just 2D ConvNets random_tensor = keep_prob + torch.rand(shape, dtype=x.dtype, device=x.device) random_tensor.floor_() # binarize output = x.div(keep_prob) * random_tensor return output 详细讲解一下
这是一个函数,用于在残差块的主路径上每个样本中丢弃路径(随机深度)。如果在EfficientNet等网络中使用,则与我创建的DropConnect实现相同,但原始名称会导致误解,因为“Drop Connect”是另一篇论文中不同形式的丢失连接。详见讨论:https://github.com/tensorflow/tpu/issues/494. 其中,x为输入的张量,drop_prob为float类型,表示丢弃概率,默认值为0,training为布尔类型,表示是否训练,默认为False。
def create_dataset(dataset_path, batch_size=8, train_image_size=224, do_train=False): """ create a train or evaluate flowers dataset for resnet50 Args: dataset_path(string): the path of dataset. do_train(bool): whether dataset is used for train or eval. batch_size(int): the batch size of dataset. Default: 8 Returns: dataset """ if do_train: trans = [RandomCropDecodeResize(size=(224, 224)), RandomHorizontalFlip(prob=0.5), Rescale(1.0 / 255.0, 0.0), Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225]), HWC2CHW()] else: trans = [RandomCropDecodeResize(size=(256, 256)), CenterCrop(224), Rescale(1.0 / 255.0, 0.0), Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225]), HWC2CHW()] type_cast_op = ts.c_transforms.TypeCast(ms.int32) dataset_loader = ds.ImageFolderDataset(dataset_dir=dataset_path) dataset_trans = dataset_loader.map(operations=trans, input_columns="image", num_parallel_workers=get_num_parallel_workers(8)) dataset_trans = dataset_trans.map(operations=type_cast_op, input_columns="label", num_parallel_workers=get_num_parallel_workers(8)) data_set = dataset_trans.batch(batch_size=batch_size, drop_remainder=True) return data_set
这是一个用于创建训练或评估数据集的函数。它接受以下参数:dataset_path(数据集路径)、batch_size(批处理大小,默认为8)、train_image_size(训练图像大小,默认为224)、do_train(是否用于训练,默认为False)。
如果do_train为True,将使用一系列数据增强操作来处理数据集。这些操作包括:随机裁剪、随机水平翻转、缩放、归一化和通道转换。
如果do_train为False,将使用另一组数据增强操作来处理数据集。这些操作包括:随机裁剪、中心裁剪、缩放、归一化和通道转换。
接着,将使用ImageFolderDataset加载数据集,并将之前定义的数据增强操作应用到数据集上。然后,通过batch方法将数据集分成批次,并使用drop_remainder参数删除不完整的批次。
最后,返回处理后的数据集。
注意:在代码中存在一些未定义的函数和变量(如get_num_parallel_workers),你可能需要提供这些定义。
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