Produce a matrix from pointwise outer product from vectors of different length

I have 3 by 1 vectors

u, v1, v2, v3.

I also have a 1 by 9 vector

v = [v1' v2' v3']

concatenating the conjugate of vi.

How can I produce a 3 by 9 matrix w such that

w = [u*v1' u*v2' u*v3'];

where

u*v1', u*v2', and u*v3'

are all 3 by 3.

[Walter Roberson]

You cannot. You have three sub-matrices each 3 x 3, for a total of 3 * 3 * 3 = 27 elements, but you want a 9 x 9 output matrix which calls for 9 * 9 = 81 elements. The content of the other 54 elements is not defined.

[K.E.]

@Walter Roberson oh sorry 3 by 9.

Answer 1

[Walter Roberson]

u * v

would be the same as

u * [v1', v2', v3']

which would be the same as

[u * v1', u*v2', u*v3']

so just go ahead and use u * v