from_numpy() automatically inherits input array dtype. On the other hand, torch.Tensor is an alias for torch.FloatTensor.
Therefore, if you pass int64 array to torch.Tensor, output tensor is float tensor and they wouldn't share the storage. torch.from_numpy gives you torch.LongTensor as expected.
a = np.arange(10)
ft = torch.Tensor(a) # same as torch.FloatTensor
it = torch.from_numpy(a)
a.dtype # == dtype('int64')
ft.dtype # == torch.float32
it.dtype # == torch.int64
Answer from Viacheslav Kroilov on Stack Overflowfrom_numpy() automatically inherits input array dtype. On the other hand, torch.Tensor is an alias for torch.FloatTensor.
Therefore, if you pass int64 array to torch.Tensor, output tensor is float tensor and they wouldn't share the storage. torch.from_numpy gives you torch.LongTensor as expected.
a = np.arange(10)
ft = torch.Tensor(a) # same as torch.FloatTensor
it = torch.from_numpy(a)
a.dtype # == dtype('int64')
ft.dtype # == torch.float32
it.dtype # == torch.int64
The recommended way to build tensors in Pytorch is to use the following two factory functions: torch.tensor and torch.as_tensor.
torch.tensor always copies the data. For example, torch.tensor(x) is equivalent to x.clone().detach().
torch.as_tensor always tries to avoid copies of the data. One of the cases where as_tensor avoids copying the data is if the original data is a numpy array.