Method f_backward

test/test_proxy_tensor.py:410–413

(x)

            return torch.autograd.grad(val, x)

        def f_backward(x):
            val = x.cos().cos().sum()
            val.backward()
            return x.grad

        for f in [f_grad, f_backward]:
            self._test(f, [torch.randn(3, requires_grad=True)])