Sorry, I should have explained a bit better for the community…
So my understanding is an error like this…
RuntimeError: for output no. 0,
numerical:(
1 0 0 … 0 0 0
0 1 0 … 0 0 0
0 0 1 … 0 0 0
… ⋱ …
0 0 0 … 1 0 0
0 0 0 … 0 1 0
0 0 0 … 0 0 1
[torch.FloatTensor of size 150x150]
,)
analytical:(
0 0 0 … 0 0 0
0 0 0 … 0 0 0
0 0 0 … 0 0 0
… ⋱ …
0 0 0 … 0 0 0
0 0 0 … 0 0 0
0 0 0 … 0 0 0
[torch.FloatTensor of size 150x150]
,)
The giveaway is the matrix of Zeros on the “analytical” result.  All the grads are Zero!  I guess this means that somewhere in the computation graph, autograd lost track of the gradients.  Possibly by passing through a Variable I wrote that didn’t have gradients in it.
That’s how Im interpreting that result.
So I’m checking all my Variables to make sure the ones that should have gradients do have them.