| """FractalBlock: fractal transformer block (minimal L2a + full L2b).
|
|
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| L2a: x -> LayerNorm -> FractalLinearAttention -> Dropout -> + x (residual)
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| L2b: x -> LN -> attn -> +x -> LN -> Kuramoto -> phases -> LN -> MoE -> +x
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| """
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|
|
| import torch
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| import torch.nn as nn
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|
|
| from .attention import FractalLinearAttention
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| from .phase_ode import KuramotoLayer
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| from .moe import PhaseRoutedMoE
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|
|
|
|
| class FractalBlock(nn.Module):
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| """Minimal fractal transformer block (L2a).
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|
|
| Args:
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| d_model : model dimension.
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| n_heads : number of attention heads.
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| d_head : dimension per head (n_heads·d_head == d_model required).
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| n_levels : fractal levels of the attention.
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| dropout : dropout rate (0 by default in L2a, will be added in L7).
|
| """
|
|
|
| def __init__(
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| self,
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| d_model: int,
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| n_heads: int,
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| d_head: int,
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| n_levels: int = 3,
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| dropout: float = 0.0,
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| ):
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| super().__init__()
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| self.norm = nn.LayerNorm(d_model)
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| self.attn = FractalLinearAttention(d_model, n_heads, d_head, n_levels)
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| self.dropout = nn.Dropout(dropout) if dropout > 0 else nn.Identity()
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|
|
| def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| """x: (B, L, d_model) → (B, L, d_model).
|
|
|
| Residual connection: out = x + dropout(attn(norm(x))).
|
| """
|
| return x + self.dropout(self.attn(self.norm(x)))
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|
|
|
|
| class FractalBlockFull(nn.Module):
|
| """Full fractal transformer block (L2b): integrates Kuramoto + MoE.
|
|
|
| Architecture:
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| x → LN → FractalLinearAttention → + x (residual 1)
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| → LN → KuramotoLayer → phases
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| → LN → PhaseRoutedMoE(hidden, phases) → + x (residual 2)
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|
|
| Returns (output, loss_aux) where loss_aux is the MoE load_balance_loss
|
| (to be added to the main loss by the caller).
|
| """
|
|
|
| def __init__(
|
| self,
|
| d_model: int,
|
| n_heads: int,
|
| d_head: int,
|
| n_levels: int,
|
| n_oscillators: int,
|
| coupling_rank: int,
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| n_experts: int,
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| top_k: int,
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| kappa: float = 4.0,
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| kuramoto_steps: int = 4,
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| kuramoto_dt: float = 0.1,
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| dropout: float = 0.0,
|
| ):
|
| super().__init__()
|
|
|
| self.norm1 = nn.LayerNorm(d_model)
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| self.attn = FractalLinearAttention(d_model, n_heads, d_head, n_levels)
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|
|
| self.norm_kur = nn.LayerNorm(d_model)
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| self.kuramoto = KuramotoLayer(d_model, n_oscillators, coupling_rank,
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| n_steps=kuramoto_steps, dt=kuramoto_dt)
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| self.norm_moe = nn.LayerNorm(d_model)
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| self.moe = PhaseRoutedMoE(d_model, n_experts, top_k, kappa=kappa)
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| self.dropout = nn.Dropout(dropout) if dropout > 0 else nn.Identity()
|
|
|
| def forward(self, x: torch.Tensor):
|
| """x: (B, L, d_model) → (output (B, L, d_model), loss_aux scalar)."""
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|
|
| x = x + self.dropout(self.attn(self.norm1(x)))
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|
|
| phases = self.kuramoto(self.norm_kur(x))
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|
|
| moe_out, lb_loss = self.moe(self.norm_moe(x), phases)
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| x = x + self.dropout(moe_out)
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| return x, lb_loss
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|
|