Hello, say I have
A = torch.rand(vec_len,1)
B = torch.rand(vec_len,1)
C = torch.rand(vec_len,1)

and I want to create a tensor T, the shape of which is (vec_len,3,3) and its i_th channel would be like this:
[[Ai, 0,  0],
 [0,  0, Bi],
 [0,  Ci, 0]]

How can I fast create such a tensor? Thanks!