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?
Best Answer
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 writeF = 1.*B + 2.*C + 3.*DG = 4.*B + 5.*C + 6.*DH = 7.*B + 8.*C + 9.*D