RuntimeError: Expected object of scalar type Double but got scalar type Float for argument #2 'mat2'

解决方法是将用到的数据进行类型转换：

原来：

prediction, h_state = rnn(x, h_state)

加上类型转换：

x = torch.tensor(x, dtype=torch.float32)
prediction, h_state = rnn(x, h_state)