util.py 文件源码

def get_dropout_mask(dropout_probability: float, tensor_for_masking: torch.autograd.Variable):
    """
    Computes and returns an element-wise dropout mask for a given tensor, where
    each element in the mask is dropped out with probability dropout_probability.
    Note that the mask is NOT applied to the tensor - the tensor is passed to retain
    the correct CUDA tensor type for the mask.

    Parameters
    ----------
    dropout_probability : float, required.
        Probability of dropping a dimension of the input.
    tensor_for_masking : torch.Variable, required.


    Returns
    -------
    A torch.FloatTensor consisting of the binary mask scaled by 1/ (1 - dropout_probability).
    This scaling ensures expected values and variances of the output of applying this mask
     and the original tensor are the same.
    """
    binary_mask = tensor_for_masking.clone()
    binary_mask.data.copy_(torch.rand(tensor_for_masking.size()) > dropout_probability)
    # Scale mask by 1/keep_prob to preserve output statistics.
    dropout_mask = binary_mask.float().div(1.0 - dropout_probability)
    return dropout_mask