PyTorch installation and foundation

PyTorch installation:

  https://pytorch.org/get-started/locally/ 

PyTorch basis:

  Tensor: comprises zero-dimensional (constant), a one-dimensional (array / list / tuple), a two-dimensional (matrix) ......

  Tensor of creation:

    torch.tensor (list / array / tuple) # the array / list / set into tensor

    torch.ones ([2,3]) # create the shape of a [2,3], and the tensor elements are all 1

    torch.zeros ([2,3]) # create the shape of a [2,3], and the tensor elements are all 0

    torch.empty ([2,3]) # create the shape of a [2,3], the element normally distributed tensor

    torch.rand ([2,3]) # Create shape [2,3], the elements of the tensor 0-1

    torch.randn ([2,3]) # Create a shape of [2,3], the element mean of 0 and standard deviation of the array 1

    torch.randint (low, high, size = []) to generate a specified size, low-high, see element is a random integer tensor

  tensor properties:

    tensor.item () tensor only one element for acquiring the element (s elements being given)

    tensor and numpy conversion:

      np_ts = tensor.numpy()

      ts = torch.tensor(np_ts)

    tensor.size (dim) tensor shape (direction can be specified)

    tensor.view (size) changes shape tensor

    tensor.t (0,1) tensor transpose (the dimension can be specified)

  tensor slice and the index:

    Similar to the numpy

  tensor methods:

    tensor.max (dim) to obtain the largest element (can specify dimensions, will also return index) tensor in

  tensor data type:

    tensor.dtype view tensor data types

    tensor.int () into int32

    tensor.long () into int64

    tensor.float () into float32

    tensor.double () into float64

  tensor calculation:

    tensor + // * // tensor matrix shape corresponding to the same operating position (if different shapes, satisfying the conditions of the broadcast, may be broadcast operation)

    tensor + // * // Digital  

    tensor1.add_ (tensor2) after adding tensor assigned tensor1

  CUDA type:

    device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")

    torch.tensor ([2,3], device) # Create a tensor type of cuda

    tensor.to (device) # will have created a good type of tensor tensor into cuda

    tensor.cpu () # cuda the type tensor into cpu type tensor

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Origin www.cnblogs.com/nanhua097/p/11194743.html