权重共享技术:通过聚类与哈希减少参数数量
python import torch import torch.nn as nn from sklearn.cluster import KMeans
1. 训练得到一个原始模型(此处假设已训练好)
original_weights = torch.randn(256, 512) # 示例权重
2. 展平权重并聚类
weights_np = original_weights.detach().numpy().ravel().reshape(-1, 1) k = 256 kmeans = KMeans(n_clusters=k, random_state=0).fit(weights_np) centroids = torch.tensor(kmeans.cluster_centers_.squeeze(), dtype=torch.float32) assignments = torch.tensor(kmeans.labels_, dtype=torch.long).view(original_weights.shape)
3. 构建压缩层
class ClusteredLinear(nn.Module): def init(self, centroids, assignments, bias=None): super().init() self.centroids = nn.Parameter(centroids) # 可学习质心 self.register_buffer('assignments', assignments) # 固定分配 if bias is not None: self.bias = nn.Parameter(bias) else: self.bias = None
def forward(self, x):
# 根据 assignments 索引 centroids,重建权重矩阵
weight = self.centroids[self.assignments]
return nn.functional.linear(x, weight, self.bias)
4. 初始化压缩层并微调
clustered_layer = ClusteredLinear(centroids, assignments) optimizer = torch.optim.SGD(clustered_layer.parameters(), lr=0.01)
模拟几步训练
for _ in range(100): input_tensor = torch.randn(64, 256) output = clustered_layer(input_tensor) loss = output.sum() # 占位损失 optimizer.zero_grad() loss.backward() optimizer.step()