Numpy 2-D & 3-D matrix “row”-wise multiplication

Question

I started learning numpy and I\'m trying to do a kind of strange matrix multiplication between a 2-dimensional and a 3-dimensional matrices. I have a function that does what

Answer 1

You can use np.einsum -

np.einsum('ij,ijk->ik',array1,array2)

Or with np.matmul or @ operator on Python 3.x -

np.matmul(array1[:,None,:],array2)[:,0]
(array1[:,None,:] @ array2)[:,0]