I have a matrix of scalars (A):

    1  2  3 
    4  5  6 
    7  8  9 

And 3 other matrices of the same size (100X200), B,C,D.

I want to do the following:

A*[B,C,D] so that the outcome will be [1*B 2*C 3*D, 4*B 5*C 6*D, 7*B 8*C 9*D].

Using normal multiplication * does not work since [B,C,D] obviously isn't of size 3X3. How can it be done correctly?

CodePudding user response：

• What you want to do is this giant sparse matrix multiplication

  

  where I is the identity matrix, and the above are stacked vectors and matrix where all the rows and columns are appended together.

• What you should do as mentioned in the comments is to use the .* operator to write

  F = 1.*B   2.*C   3.*D
  G = 4.*B   5.*C   6.*D
  H = 7.*B   8.*C   9.*D