feat: implement dynamic threshold scheduling for GraphMixer

This commit is contained in:
gameloader
2025-09-12 17:02:42 +08:00
parent 6a1f9d30f3
commit 172328a4e6
4 changed files with 105 additions and 41 deletions

View File

@ -53,6 +53,10 @@ class HierarchicalGraphMixer(nn.Module):
dim: int,
max_degree: int = None, # 可选:限制每行最多边数
thr: float = 0.5, # 保留边阈值,例如 0.5/0.7
thr_min: float = None, # 动态阈值起点,不传则用 thr
thr_max: float = None, # 动态阈值终点,不传则用 thr
thr_steps: int = 0, # 从 thr_min -> thr_max 的步数,>0 时启用动态调度
thr_schedule: str = "linear", # "linear" | "cosine" | "exp"
temperature: float = 2./3.,
tau_attn: float = 1.0, # Patch attention 温度(可选)
symmetric: bool = True, # 是否对称化通道图
@ -67,6 +71,13 @@ class HierarchicalGraphMixer(nn.Module):
self.tau_attn = tau_attn
self.symmetric = symmetric
self.degree_rescale = degree_rescale
self.thr_min = thr if (thr_min is None) else float(thr_min)
self.thr_max = thr if (thr_max is None) else float(thr_max)
self.thr_steps = int(thr_steps) if thr_steps is not None else 0
self.thr_schedule = thr_schedule
self._use_dynamic_thr = (self.thr_steps > 0) and (abs(self.thr_max - self.thr_min) > 1e-12)
# 用 buffer 记录已步进次数(不保存到权重里)
self.register_buffer("_thr_step", torch.zeros((), dtype=torch.long), persistent=False)
# Level 1: 非归一化门控
self.gate = HardConcreteGate(
@ -88,6 +99,30 @@ class HierarchicalGraphMixer(nn.Module):
self.out_proj = nn.Linear(dim, dim)
self.norm = nn.LayerNorm(dim)
def _compute_thr_by_progress(self, progress: float) -> float:
# progress in [0,1]
progress = max(0.0, min(1.0, float(progress)))
if self.thr_schedule == "linear":
g = progress
elif self.thr_schedule == "cosine":
# 慢起步,后期加速
import math
g = 0.5 - 0.5 * math.cos(math.pi * progress)
elif self.thr_schedule == "exp":
# 更快从 thr_min 过渡到 thr_max指数式
import math
k = 5.0
g = (math.exp(k * progress) - 1.0) / (math.exp(k) - 1.0)
else:
g = progress
return self.thr_min + (self.thr_max - self.thr_min) * g
def _maybe_update_thr(self):
if self.training and self._use_dynamic_thr:
step = int(self._thr_step.item())
progress = step / float(self.thr_steps)
self.thr = float(self._compute_thr_by_progress(progress))
self._thr_step += 1
def _build_sparse_neighbors(self, z_gate):
"""
基于 z_gate 构造每行的邻接列表按阈值与可选top-k
@ -151,6 +186,7 @@ class HierarchicalGraphMixer(nn.Module):
return lam * self.gate.expected_l0().sum()
def forward(self, z):
self._maybe_update_thr()
# z: [B, C, N, D]
B, C, N, D = z.shape
assert C == self.C and D == self.dim

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@ -30,6 +30,10 @@ class SeasonPatch(nn.Module):
headdim: int = 64,
# Mixergraph 可选超参数
thr_graph: float = 0.5,
thr_graph_min: float = None,
thr_graph_max: float = None,
thr_graph_steps: int = 0,
thr_graph_schedule: str = "linear",
symmetric_graph: bool = True,
degree_rescale: str = "count-sqrt", # "none" | "count" | "count-sqrt" | "sum"
gate_temperature: float = 2./3.,
@ -38,6 +42,9 @@ class SeasonPatch(nn.Module):
super().__init__()
# ===== 新增:保存 l0_lambda防止 reg_loss 访问报错 =====
self.l0_lambda = l0_lambda
# Store patch parameters
self.patch_len = patch_len # patch 长度
self.stride = stride # patch 步幅
@ -60,6 +67,10 @@ class SeasonPatch(nn.Module):
dim=d_model,
max_degree=k_graph,
thr=thr_graph,
thr_min=thr_graph_min,
thr_max=thr_graph_max,
thr_steps=thr_graph_steps,
thr_schedule=thr_graph_schedule,
temperature=gate_temperature,
tau_attn=tau_attn,
symmetric=symmetric_graph,