I'm trying to compute a matrix H as follows:
Where L is a tensor of shape (?,N) and z is a variable vector shape (M).
Each element of H is a broadcast product of 2 gradients of L which respect to two elements of vector z.
The tf.gradients(L,z[i]) * tf.gradients(L,z[j]) does not work because it returns a product of two sum, while I need a sum of wise products. Anyone have done that before, please help me.