Torch 运算符 @ 和 *

'@' ： 矩阵乘
'*' ： 矩阵点乘

>>a = torch.tensor([[1, 2],
                   [3, 4]])
>>b = torch.tensor([[4, 5],
                    [6, 7]])
>>print(f'a x b = {a @ b}\na * b = {a * b}')

>>a x b = tensor([[16, 19],
                  [36, 43]])
  a * b = tensor([[ 4, 10],
                  [18, 28]])