multiplying 5*5 matrix to a vector on an element by element basis using loops

Hi all,

i need to write a code that multiplies the matrix A and the vector B defined below on an element-by-element basis using loops in my code.

A = [1 12 22 10 18; 20 8 13 2 25; 6 19 3 23 14; 4 24 17 15 7; 11 21 16 5 9];

B = [9 7 11 4 23];

thanks in advance for your support

[James Tursa]

What have you done so far? What specific problems are you having with your code? The algorithm can be found here:

https://en.wikipedia.org/wiki/Matrix_multiplication

[mohamed samhy]

i need help using loops to multiply element by element

Answer 1

[Victor]

Are you required to use for loops to multiply element by element here or could you make use of standard Matlab functionality such as the code snippet below?

C = A .* B;

One way of doing this using for loops is shown below

C = zeros(size(A)); % preallocate C
for i = 1:size(A,1) 
    for k = 1:size(A,2)
        C(i,k) = A(i,k) * B(k);
    end
end