100 lines
3.9 KiB
Python
100 lines
3.9 KiB
Python
"""
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SeasonPatch = PatchTST (CI) + ChannelGraphMixer + Linear prediction head
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支持两种编码器：
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- Transformer 编码器路径：PatchTST + GraphMixer + Head
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- Mamba2 编码器路径：Mamba2Encoder（不使用mixer），直接用最后得到的 d_model 走 Head
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"""
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import torch
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import torch.nn as nn
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from layers.TSTEncoder import TSTiEncoder
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from layers.GraphMixer import HierarchicalGraphMixer
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from layers.MambaSeries import Mamba2Encoder
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class SeasonPatch(nn.Module):
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def __init__(self,
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c_in: int,
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seq_len: int,
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pred_len: int,
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patch_len: int,
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stride: int,
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k_graph: int = 8,
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encoder_type: str = "Transformer",
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d_model: int = 128,
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n_layers: int = 3,
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n_heads: int = 16,
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# Mamba2 相关可选超参
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d_state: int = 64,
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d_conv: int = 4,
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expand: int = 2,
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headdim: int = 64):
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super().__init__()
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# Store patch parameters
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self.patch_len = patch_len # patch 长度
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self.stride = stride # patch 步幅
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# Calculate patch number
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patch_num = (seq_len - patch_len) // stride + 1 # patch_num: int
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self.encoder_type = encoder_type
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# 只初始化需要的encoder
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if encoder_type == "Transformer":
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# Transformer (PatchTST) 编码器（channel independent）
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self.encoder = TSTiEncoder(
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c_in=c_in, patch_num=patch_num, patch_len=patch_len,
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d_model=d_model, n_layers=n_layers, n_heads=n_heads
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)
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self.mixer = HierarchicalGraphMixer(c_in, dim=d_model, k=k_graph)
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# Prediction head（Transformer 路径用到，输入维度为 patch_num * d_model）
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self.head = nn.Sequential(
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nn.Linear(patch_num * d_model, patch_num * d_model),
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nn.SiLU(),
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nn.Linear(patch_num * d_model, pred_len)
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)
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elif encoder_type == "Mamba2":
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# Mamba2 编码器（channel independent），返回 [B, C, d_model]
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self.encoder = Mamba2Encoder(
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c_in=c_in, patch_num=patch_num, patch_len=patch_len,
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d_model=d_model, d_state=d_state, d_conv=d_conv,
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expand=expand, headdim=headdim
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)
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# Prediction head（Mamba2 路径用到，输入维度为 d_model）
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self.head = nn.Sequential(
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nn.Linear(d_model, d_model),
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nn.SiLU(),
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nn.Linear(d_model, pred_len)
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)
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else:
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raise ValueError(f"Unsupported encoder_type: {encoder_type}")
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def forward(self, x ):
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# x: [B, L, C]
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x = x.permute(0, 2, 1) # x: [B, C, L]
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# Patch the input
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x_patch = x.unfold(-1, self.patch_len, self.stride) # x_patch: [B, C, patch_num, patch_len]
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if self.encoder_type == "Transformer":
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# Encode patches (PatchTST)
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z = self.encoder(x_patch) # z: [B, C, d_model, patch_num]
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# [B, C, d_model, patch_num] -> [B, C, patch_num, d_model]
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B, C, D, N = z.shape # B: batch, C: channels, D: d_model, N: patch_num
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z = z.permute(0, 1, 3, 2) # z: [B, C, patch_num, d_model]
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# Cross-channel mixing
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z_mix = self.mixer(z) # z_mix: [B, C, patch_num, d_model]
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# Flatten and predict
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z_mix = z_mix.view(B, C, N * D) # z_mix: [B, C, patch_num * d_model]
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y_pred = self.head(z_mix) # y_pred: [B, C, pred_len]
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elif self.encoder_type == "Mamba2":
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# 使用 Mamba2 编码器（不使用 mixer）
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z_last = self.encoder(x_patch) # z_last: [B, C, d_model]（仅最后一个时间步）
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y_pred = self.head(z_last) # y_pred: [B, C, pred_len]
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return y_pred # [B, C, pred_len]
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