能给出具体的优化代码吗
时间: 2023-06-14 11:04:55 浏览: 87
优化代码取决于具体的应用场景和模型结构,下面是一些常用的优化技巧及其代码实现:
1. 批量归一化(Batch Normalization):
```python
class BatchNorm(nn.Module):
def __init__(self, num_features, eps=1e-5, momentum=0.1):
super(BatchNorm, self).__init__()
self.num_features = num_features
self.eps = eps
self.momentum = momentum
self.weight = nn.Parameter(torch.Tensor(num_features))
self.bias = nn.Parameter(torch.Tensor(num_features))
self.register_buffer('running_mean', torch.zeros(num_features))
self.register_buffer('running_var', torch.ones(num_features))
self.reset_parameters()
def reset_parameters(self):
self.weight.data.uniform_()
self.bias.data.zero_()
def forward(self, x):
if self.training:
mean = x.mean(dim=0, keepdim=True)
var = x.var(dim=0, keepdim=True)
self.running_mean = (1 - self.momentum) * self.running_mean + self.momentum * mean
self.running_var = (1 - self.momentum) * self.running_var + self.momentum * var
else:
mean = self.running_mean
var = self.running_var
x = (x - mean) / torch.sqrt(var + self.eps)
x = self.weight * x + self.bias
return x
```
2. Dropout:
```python
class Dropout(nn.Module):
def __init__(self, p=0.5):
super(Dropout, self).__init__()
self.p = p
def forward(self, x):
if not self.training or self.p == 0:
return x
mask = (torch.rand(x.shape) > self.p).float().to(x.device)
x = x * mask / (1 - self.p)
return x
```
3. 权重衰减(Weight Decay):
```python
optimizer = torch.optim.Adam(model.parameters(), lr=lr, weight_decay=weight_decay)
```
4. 学习率衰减(Learning Rate Decay):
```python
scheduler = torch.optim.lr_scheduler.StepLR(optimizer, step_size=lr_decay_step, gamma=lr_decay_rate)
```
5. 渐进式训练(Progressive Training):
```python
for i in range(num_finetune_steps):
if i < num_warmup_steps:
lr = init_lr * (i + 1) / num_warmup_steps
else:
lr = init_lr * (1 - (i - num_warmup_steps) / (num_finetune_steps - num_warmup_steps))
optimizer = torch.optim.Adam(model.parameters(), lr=lr, weight_decay=weight_decay)
train(model, optimizer, ...)
```
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