File size: 5,128 Bytes
fb4abf6
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
import torch
import torch.nn as nn


class MLP(nn.Module):
    def __init__(self, in_dim: int, out_dim: int, hidden: int = 128, dropout: float = 0.05):
        super().__init__()
        self.net = nn.Sequential(
            nn.Linear(in_dim, hidden//2),
            nn.GELU(),
            nn.Dropout(dropout),
            nn.Linear(hidden//2, hidden),
            nn.GELU(),
            nn.Dropout(dropout),
            nn.Linear(hidden, out_dim)
        )

    def forward(self, x):
        return self.net(x)

class YieldTransformer(nn.Module):
    def __init__(
        self,
        w_dim: int,
        soil_dim: int,
        d_model: int = 128,
        nhead: int = 4,
        num_layers: int = 2,
        dim_ff: int = 256,
        dropout: float = 0.05,
        use_crop: bool = True,
        crop_emb_dim: int = 8,
        max_weeks: int = 32,
        pool: str = "mean", # Changed default to mean
        farm_emb_dim: int = 8,
        horizon_emb_dim: int = 16,
    ):
        super().__init__()
        assert pool in ["last", "cls", "mean"]
        self.pool = pool
        self.use_crop = use_crop
        self.max_weeks = max_weeks

        crop_in = crop_emb_dim if use_crop else 0
        if use_crop:
            self.crop_emb = nn.Embedding(2, crop_emb_dim)

        self.horizon_emb = nn.Embedding(max_weeks + 1, horizon_emb_dim)
        self.horizon_proj = nn.Linear(horizon_emb_dim, d_model)

        self.week_proj = nn.Linear(1, d_model) 

        self.weather_enc = MLP(w_dim + crop_in, d_model, hidden=d_model, dropout=dropout)
        self.soil_enc = MLP(soil_dim + crop_in, d_model, hidden=d_model, dropout=dropout)

        self.ws_cross_attn = nn.MultiheadAttention(
            embed_dim=d_model,
            num_heads=nhead,
            dropout=dropout,
            batch_first=True,
        )
        self.ws_ln = nn.LayerNorm(d_model)

        self.pos_emb = nn.Parameter(torch.zeros(1, max_weeks + 1, d_model))
        nn.init.trunc_normal_(self.pos_emb, std=0.02)

        if pool == "cls":
            self.cls_token = nn.Parameter(torch.zeros(1, 1, d_model))
            nn.init.trunc_normal_(self.cls_token, std=0.02)

        enc_layer = nn.TransformerEncoderLayer(
            d_model=d_model, nhead=nhead, dim_feedforward=dim_ff,
            dropout=dropout, activation="gelu", batch_first=True, norm_first=True,
        )
        self.temporal_tf = nn.TransformerEncoder(enc_layer, num_layers=num_layers)

        self.head = nn.Sequential(
            nn.LayerNorm(d_model + horizon_emb_dim + d_model), 
            nn.Linear(d_model + horizon_emb_dim + d_model, d_model),
            nn.GELU(),
            nn.Dropout(dropout),
            nn.Linear(d_model, 1),
        )

    def forward(
        self,
        weather,
        soil,
        crop_id,
        farm_field_encoded=None, 
        week_mask=None,
        causal=False,
        return_sequence=False,
        horizon_idx=None,
    ):
        B, t, W = weather.shape
        device = weather.device


        if horizon_idx is None: horizon_idx = torch.tensor(t, device=device).expand(B)
        if not torch.is_tensor(horizon_idx): horizon_idx = torch.tensor(horizon_idx, device=device).expand(B)
        
        h_idx = horizon_idx.long().clamp(min=1, max=self.max_weeks)
        h_emb = self.horizon_emb(h_idx)
        h_tok = self.horizon_proj(h_emb) 

        if self.use_crop:
            c = self.crop_emb(crop_id)
            weather_in = torch.cat([weather, c[:, None, :].expand(-1, t, -1)], dim=-1)
            soil_in = torch.cat([soil, c], dim=-1)
        else:
            weather_in, soil_in = weather, soil

        w_tok = self.weather_enc(weather_in)
        s_encoded = self.soil_enc(soil_in) 

        fused = self.ws_ln(w_tok + s_encoded[:, None, :])
        fused = fused + h_tok[:, None, :] 

        weeks = torch.arange(1, t + 1, device=device).float() / self.max_weeks
        week_signal = self.week_proj(weeks[None, :, None].expand(B, -1, -1))
        
        x = fused + week_signal + self.pos_emb[:, :t, :]
        
        if self.pool == "cls":
            x = torch.cat([self.cls_token.expand(B, -1, -1), x], dim=1)
            t_idx = t + 1
        else: t_idx = t

        src_key_padding_mask = ~week_mask.bool() if week_mask is not None else None

        attn_mask = None
        if causal:
            L = x.size(1)
            attn_mask = torch.triu(
                torch.ones(L, L, device=device, dtype=torch.bool),
                diagonal=1,
            )

        h = self.temporal_tf(
            x,
            mask=attn_mask,
            src_key_padding_mask=src_key_padding_mask,
        )

        if self.pool == "mean":
            if week_mask is not None:
                mask = week_mask.unsqueeze(-1).float()
                pooled = (h * mask).sum(dim=1) / mask.sum(dim=1).clamp(min=1e-9)
            else:
                pooled = h.mean(dim=1)
        elif self.pool == "cls":
            pooled = h[:, 0, :]
        else: 
            pooled = h[:, -1, :]

        out = torch.cat([pooled, h_emb, s_encoded], dim=-1)
        return self.head(out).squeeze(-1)