element in matrix multiplication to create a new matrix

A and O is 3x1 matrix

B and D is 1x3 matrix

f is a 3x3 matrix

What is wrong with the code below?

i=1:3

j=1:3

T(i,j)=A(i).*B(j).*O(i).*D(j).*f(i,j)

Answer 1

[Marta Salas]

Your code doesn't run because you are using .* which is element wise multiplication instead of standar matrix multiplication. You can do:

for i=1:3
    for j=1:3
        T(i,j)=A(i).*B(j).*O(i).*D(j).*f(i,j)
    end
end

or

T=A*B*O*D*f

depending on the result you are expecting.

Answer 2

[Benjamin Avants]

Your question is a little unclear, but if you want to do matrix multiplication like this:

          |d|
|a,b,c| * |e| = (ad+be+fc)
          |f|

or this

|a|             |ae,af,ag|
|b| * |e,f,g| = |be,bf,bg|
|c|             |ce,cf,cg|

then you want to use the normal * operator and not the .* operator.

The .* operator will multiply a constant by each element in the matrix or array. It will also do elementwise multiplication on arrays of the same size.

Example:

|a,b|    |e,f|   |ae,bf|
|c,d| .* |g,h| = |ag,dh|