Q1：def train() 中的model.train()的作用是什么？为什么要写？
A1：class torch.nn.Module中 train(mode=True)
Sets the module in training mode. This has any effect only on modules such as Dropout or BatchNorm.
参看 http://pytorch.org/docs/master/nn.html
Q2：torch.gather() 和 torch.norm() 函数的功能是什么？
1 t = torch.Tensor([[1, 2], [3, 4]]) 2 print(t) 3 a = torch.gather(t, 1, torch.LongTensor([[0,0], [1,0]])) 4 print(a) 5 ‘‘‘ 6 1 2 7 3 4 8 [torch.FloatTensor of size 2x2] 9 10 1 1 11 4 3 12 [torch.FloatTensor of size 2x2] 13 ‘‘‘
和
1 a = torch.FloatTensor([[1, 2], [3, 4]]) 2 b = torch.norm(a) 3 print(a) 4 print(b) 5 ‘‘‘ 6 1 2 7 3 4 8 [torch.FloatTensor of size 2x2] 9 10 5.477225575051661 11 ‘‘‘
原文：http://www.cnblogs.com/Joyce-song94/p/7252206.html