Multiplication/division Of 2d Numpy Arrays To Produce 3d Array

I am looking for a fast (ie vectorized) method to replace the following loop. I have 2 numpy arrays with dimensions: (20738,14) and (31,14). I need to multiply them element-wise to

Solution 1:

Just use broadcasting:

v.shape
# (20738, 14)
MU.shape
# (31, 14)

v_mu_3d = v[:, None, :] * MU
p2_3d = v[:, None, :] / MU

v_mu_3d.shape
# (20738, 31, 14)
p2_3d.shape
# (20738, 31, 14)