权重衰减

image
这个用法是怎么得知的,我看官方文档也没有这种用法

大佬牛逼!!所以正则化方式,lambda的取值在贝叶斯统计上相当于对w的先验分布的分布方式及对应参数的选择 :v:

特地注册账号回复,好人一生平安 :smile: :smile: :smile: :smile: :smile: :smile:

为什么我的weight_decay只要不为0,训练和测试的误差曲线就出现震荡而不是减少?

平方范数 = 标准范数^2,个人认为
1111111111

为什么不直接调整lr变化呢,调整lr和权重衰退两种方法有什么区别呢

你好,这是我写的代码,希望能对你有所帮助,我也是新手,希望不会误导你

def train_(wd):
    net = nn.Sequential(nn.Linear(num_inputs, 1)) # define net
    for param in net.parameters(): # initialize parameters
        param.data.normal_()
    loss = nn.MSELoss(reduction='none')
    num_epochs, lr = 100, 0.003
    # 偏置参数没有衰减
    trainer = torch.optim.SGD([
        {"params":net[0].weight,'weight_decay': wd},
        {"params":net[0].bias}], lr=lr)
    for epoch in range(num_epochs):
        for X, y in train_iter:
            trainer.zero_grad()
            l = loss(net(X), y)
            l.mean().backward()
            trainer.step()
    return wd, (d2l.evaluate_loss(net, train_iter, loss), d2l.evaluate_loss(net, test_iter, loss))

def draw(wds):
    animator = d2l.Animator(xlabel='lambd', ylabel='loss', yscale='log',
                               legend=['train', 'test'])
    for wd in wds:
      wd, loss = train_(wd)
      animator.add(wd, loss)

wds = range(0, 100, 10)
draw(wds)