Returns a tensor which contains all slices of size size in the dimension dim. Step between two slices is given by step.

If sizedim is the original size of dimension dim, the size of dimension dim in the returned tensor will be (sizedim - size) / step + 1

An additional dimension of size size is appended in the returned tensor. 

> x = torch.Tensor(7)
> for i=1,7 do x[i] = i end
> print(x)

 1
 2
 3
 4
 5
 6
 7
[torch.Tensor of dimension 7]

> return  x:unfold(1, 2, 1)

 1  2
 2  3
 3  4
 4  5
 5  6
 6  7
[torch.Tensor of dimension 6x2]

> return  x:unfold(1, 2, 2)

 1  2
 3  4
 5  6
[torch.Tensor of dimension 3x2]