import torch
import torch.nn as nn
import torch.nn.functional as F
from .endec import my_Layernorm, series_decomp
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class DecoderLayer(nn.Module):
"""
Autoformer decoder layer with the progressive decomposition architecture
"""
def __init__(self, self_attention, cross_attention, d_model, c_out, d_ff=None,
moving_avg=25, dropout=0.1, activation="relu"):
super(DecoderLayer, self).__init__()
d_ff = d_ff or 4 * d_model
self.self_attention = self_attention
self.cross_attention = cross_attention
self.conv1 = nn.Conv1d(in_channels=d_model, out_channels=d_ff, kernel_size=1, bias=False)
self.conv2 = nn.Conv1d(in_channels=d_ff, out_channels=d_model, kernel_size=1, bias=False)
self.decomp1 = series_decomp(moving_avg)
self.decomp2 = series_decomp(moving_avg)
self.decomp3 = series_decomp(moving_avg)
self.dropout = nn.Dropout(dropout)
self.projection = nn.Conv1d(in_channels=d_model, out_channels=c_out, kernel_size=3, stride=1, padding=1,
padding_mode='circular', bias=False)
self.activation = F.relu if activation == "relu" else F.gelu
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def forward(self, x, cross, x_mask=None, cross_mask=None):
x = x + self.dropout(self.self_attention(
x, x, x,
attn_mask=x_mask
)[0])
x, trend1 = self.decomp1(x)
x = x + self.dropout(self.cross_attention(
x, cross, cross,
attn_mask=cross_mask
)[0])
x, trend2 = self.decomp2(x)
y = x
y = self.dropout(self.activation(self.conv1(y.transpose(-1, 1))))
y = self.dropout(self.conv2(y).transpose(-1, 1))
x, trend3 = self.decomp3(x + y)
residual_trend = trend1 + trend2 + trend3
residual_trend = self.projection(residual_trend.permute(0, 2, 1)).transpose(1, 2)
return x, residual_trend
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class Decoder(nn.Module):
"""
Autoformer encoder
"""
def __init__(self, layers, norm_layer=None, projection=None):
super(Decoder, self).__init__()
self.layers = nn.ModuleList(layers)
self.norm = norm_layer
self.projection = projection
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def forward(self, x, cross, x_mask=None, cross_mask=None, trend=None):
for layer in self.layers:
x, residual_trend = layer(x, cross, x_mask=x_mask, cross_mask=cross_mask)
trend = trend + residual_trend
if self.norm is not None:
x = self.norm(x)
if self.projection is not None:
x = self.projection(x)
return x, trend