Fix unpooling docs (pytorch#492)

Author: ngimel

torch/nn/modules/pooling.py

@@ -169,10 +169,9 @@ class MaxUnpool1d(Module):
  padding (int or tuple): Padding that was added to the input
 
  Shape:
- - Input: :math:`(N, C, H_{in}, W_{in})`
- - Output: :math:`(N, C, H_{out}, W_{out})` where
- :math:`H_{out} = padding[0] * (H_{in} - 1) * stride[0] + kernel\_size[0]`
- :math:`W_{out} = padding[1] * (W_{in} - 1) * stride[1] + kernel\_size[1]`
+ - Input: :math:`(N, C, H_{in})`
+ - Output: :math:`(N, C, H_{out})` where
+ :math:`H_{out} = (H_{in} - 1) * stride[0] - 2 * padding[0] + kernel\_size[0]` 
  or as given by :attr:`output_size` in the call operator
 
  Example:
@@ -214,8 +213,8 @@ class MaxUnpool2d(Module):
  Shape:
  - Input: :math:`(N, C, H_{in}, W_{in})`
  - Output: :math:`(N, C, H_{out}, W_{out})` where
- :math:`H_{out} = padding[0] * (H_{in} - 1) * stride[0] + kernel\_size[0]`
- :math:`W_{out} = padding[1] * (W_{in} - 1) * stride[1] + kernel\_size[1]`
+ :math:`H_{out} = (H_{in} - 1) * stride[0] -2 * padding[0] + kernel\_size[0]`
+ :math:`W_{out} = (W_{in} - 1) * stride[1] -2 * padding[1] + kernel\_size[1]`
  or as given by :attr:`output_size` in the call operator
 
  Example:
@@ -263,9 +262,9 @@ class MaxUnpool3d(Module):
  Shape:
  - Input: :math:`(N, C, D_{in}, H_{in}, W_{in})`
  - Output: :math:`(N, C, D_{out}, H_{out}, W_{out})` where
- :math:`D_{out} = padding[0] * (D_{in} - 1) * stride[0] + kernel\_size[0]`
- :math:`H_{out} = padding[1] * (H_{in} - 1) * stride[1] + kernel\_size[1]`
- :math:`W_{out} = padding[2] * (W_{in} - 1) * stride[2] + kernel\_size[2]`
+ :math:`D_{out} = (D_{in} - 1) * stride[0] - 2 * padding[0] + kernel\_size[0]`
+ :math:`H_{out} = (H_{in} - 1) * stride[1] - 2 * padding[1] + kernel\_size[1]`
+ :math:`W_{out} = (W_{in} - 1) * stride[2] - 2 * padding[2] + kernel\_size[2]`
  or as given by :attr:`output_size` in the call operator
 
  Example::