Tensor power and multiplication in pytorch
I have a matrix A and a tensor b of size (1,3) - so a vector of size 3.
I want to compute
C = b1 * A + b2 * A^2 + b3 * A^3 where ^n is the n-th power of A.
At the end, C should have the same shape as A. How can I do this efficiently?

Let's try:
A = torch.ones(1,2,3)
b_vals = torch.tensor([2,3,4])
powers = torch.tensor([1,2,3])

C = (A[...,None]**powers + b_vals).sum(-1)

Output:
tensor([[[12., 12., 12.],
         [12., 12., 12.]]])

