Gradient in triplet loss

The triplet loss example in documentation is as follows:

input1 = torch.randn(100, 128, requires_grad=True)
input2 = torch.randn(100, 128, requires_grad=True)
input3 = torch.randn(100, 128, requires_grad=True)
output = triplet_loss(input1, input2, input3)

When I check the value of input1.grad, it is coming to be None. Same for input2 and input3.
Is this as expected? If so, why is requires_grad=True needed in the tensor?


To me, the .grad is not none.
Which version of pytorch are you using?

Hi @InnovArul,
Thanks for your reply! I am using pytorch 0.4.1.post2
What would be the effect if the input1.grad is None?
Could you please suggest what should I do to rectify it?
My input1,input2,input3 are outputs of an nn.Module based network

The gradients of intermediate variables (in this case, input1,input2,input3) will be cleared by autograd during backpropagation. If you really want to retain the gradient for certain variables (for example, to visually inspect) after backpropagation, use .retain_grad() on those variables.

Thanks a lot @InnovArul! Your reply helped me find and solve a bug which was hitting my code badly! Thanks a lot!

I am glad I could be of some help! cheers.