torch.optim.Adam不能获取Parameter参数

Question

使用torch.nn.Parameter定义参数后，使用torch.optim.Adam(centerloss.parameters())出现：
"ValueError: optimizer got an empty parameter list"
代码如下：

import torch
import torch.nn as nn

class CenterLoss(nn.Module):
    def __init__(self, num_classes=10, feat_dim=2, use_gpu=True):
        super(CenterLoss, self).__init__()
        self.num_classes = num_classes
        self.feat_dim = feat_dim
        self.use_gpu = use_gpu

        if self.use_gpu:
            self.centers = nn.Parameter(torch.randn(self.num_classes, self.feat_dim).cuda())
        else:
            self.centers = nn.Parameter(torch.randn(self.num_classes, self.feat_dim))

    def forward(self, x, labels):
        batch_size = x.size(0)
        distmat = torch.pow(x, 2).sum(dim=1, keepdim=True).expand(batch_size, self.num_classes) + \
                  torch.pow(self.centers, 2).sum(dim=1, keepdim=True).expand(self.num_classes, batch_size).t()
        distmat.addmm_(1, -2, x, self.centers.t())

        classes = torch.arange(self.num_classes).long()
        if self.use_gpu: classes = classes.cuda()
        labels = labels.unsqueeze(1).expand(batch_size, self.num_classes)
        mask = labels.eq(classes.expand(batch_size, self.num_classes))

        dist = distmat * mask.float()
        loss = dist.clamp(min=1e-12, max=1e+12).sum() / batch_size

        return loss

if __name__ == "__name__":
    centerloss = CenterLoss()
    torch.optim.Adam(centerloss.parameters())
    

请帮忙解答一下这是什么原因呀

Answer 1

你的CenterLoss类中并没有定义网络层啊，所以就没有要优化的参数，所以报错传递一个空的参数列表。