paddlenlp.layers.tcn 源代码

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import paddle
import paddle.nn as nn
from paddle.nn.utils import weight_norm

__all__ = ["TemporalBlock", "TCN"]


class Chomp1d(nn.Layer):
    """
    Remove the elements on the right.

    Args:
        chomp_size (int):
            The number of elements removed.
    """

    def __init__(self, chomp_size):
        super(Chomp1d, self).__init__()
        self.chomp_size = chomp_size

    def forward(self, x):
        return x[:, :, :-self.chomp_size]


[文档]class TemporalBlock(nn.Layer): """ The TCN block, consists of dilated causal conv, relu and residual block. See the Figure 1(b) in https://arxiv.org/pdf/1803.01271.pdf for more details. Args: n_inputs (int): The number of channels in the input tensor. n_outputs (int): The number of filters. kernel_size (int): The filter size. stride (int): The stride size. dilation (int): The dilation size. padding (int): The size of zeros to be padded. dropout (float, optional): Probability of dropout the units. Defaults to 0.2. """ def __init__(self, n_inputs, n_outputs, kernel_size, stride, dilation, padding, dropout=0.2): super(TemporalBlock, self).__init__() self.conv1 = weight_norm( nn.Conv1D( n_inputs, n_outputs, kernel_size, stride=stride, padding=padding, dilation=dilation)) # Chomp1d is used to make sure the network is causal. # We pad by (k-1)*d on the two sides of the input for convolution, # and then use Chomp1d to remove the (k-1)*d output elements on the right. self.chomp1 = Chomp1d(padding) self.relu1 = nn.ReLU() self.dropout1 = nn.Dropout(dropout) self.conv2 = weight_norm( nn.Conv1D( n_outputs, n_outputs, kernel_size, stride=stride, padding=padding, dilation=dilation)) self.chomp2 = Chomp1d(padding) self.relu2 = nn.ReLU() self.dropout2 = nn.Dropout(dropout) self.net = nn.Sequential(self.conv1, self.chomp1, self.relu1, self.dropout1, self.conv2, self.chomp2, self.relu2, self.dropout2) self.downsample = nn.Conv1D(n_inputs, n_outputs, 1) if n_inputs != n_outputs else None self.relu = nn.ReLU() self.init_weights() def init_weights(self): self.conv1.weight.set_value( paddle.tensor.normal(0.0, 0.01, self.conv1.weight.shape)) self.conv2.weight.set_value( paddle.tensor.normal(0.0, 0.01, self.conv2.weight.shape)) if self.downsample is not None: self.downsample.weight.set_value( paddle.tensor.normal(0.0, 0.01, self.downsample.weight.shape))
[文档] def forward(self, x): """ Args: x (Tensor): The input tensor with a shape of [batch_size, input_channel, sequence_length]. """ out = self.net(x) res = x if self.downsample is None else self.downsample(x) return self.relu(out + res)
[文档]class TCN(nn.Layer): def __init__(self, input_channel, num_channels, kernel_size=2, dropout=0.2): """ Temporal Convolutional Networks is a simple convolutional architecture. It outperforms canonical recurrent networks such as LSTMs in many tasks. See https://arxiv.org/pdf/1803.01271.pdf for more details. Args: input_channel (int): The number of channels in the input tensor. num_channels (list | tuple): The number of channels in different layer. kernel_size (int, optional): The filter size.. Defaults to 2. dropout (float, optional): Probability of dropout the units.. Defaults to 0.2. """ super(TCN, self).__init__() layers = nn.LayerList() num_levels = len(num_channels) for i in range(num_levels): dilation_size = 2**i in_channels = input_channel if i == 0 else num_channels[i - 1] out_channels = num_channels[i] layers.append( TemporalBlock( in_channels, out_channels, kernel_size, stride=1, dilation=dilation_size, padding=(kernel_size - 1) * dilation_size, dropout=dropout)) self.network = nn.Sequential(*layers)
[文档] def forward(self, x): """ Apply temporal convolutional networks to the input tensor. Args: x (Tensor): The input tensor with a shape of [batch_size, input_channel, sequence_length]. Returns: Tensor: The `output` tensor with a shape of [batch_size, num_channels[-1], sequence_length]. """ output = self.network(x) return output