Softmax2d
class torch.nn.Softmax2d
Applies SoftMax over features to each spatial location.
When given an image of "Channels x Height x Width", it will apply
   Softmax to each location (Channels, h_i, w_j)
Shape:
      * Input: (N, C, H, W) or (C, H, W).
  * Output: (N, C, H, W) or (C, H, W) (same shape as input)

Returns:
      a Tensor of the same dimension and shape as the input with
      values in the range [0, 1]
Return type:
      None
Examples:
  >>> m = nn.Softmax2d()
  >>> # you softmax over the 2nd dimension
  >>> input = torch.randn(2, 3, 12, 13)
  >>> output = m(input)
