pytorch学习1

任何使张量就地变化的操作都用固定_。例如：x.copy_(y)，x.t_()，将改变x。

`# let us run this cell only if CUDA is available # We will use ``torch.device`` objects to move tensors in and out of GPU if torch.cuda.is_available():     device = torch.device("cuda")          # a CUDA device object     y = torch.ones_like(x, device=device)  # directly create a tensor on GPU     x = x.to(device)                       # or just use strings ``.to("cuda")``     z = x + y     print(z)     print(z.to("cpu", torch.double))       # ``.to`` can also change dtype together!`