Any way to do this using simple matrix math?

[khkwang]

Homework Statement

The following notation is as follows: a comma ',' represents a column and a semi-colon ';' represents a new row.

I have a vector:
A = [a1, a2, a3, a4, a5]

and a matrix

B = [b1, b2, b3, b4, b5;
b6, b7, b8, b9, b10;
b11, b12, b13, b14, b15]

What I want is:

C = [a1*b1, a2*b2, a3*b3, a4*b4, a5*b5;
a1*b6, a2*b7, a3*b8,a4*b9, a5*b10;
a1*b11, a2*b12, a3*b13, a4*b14, a5*b15]

Basically, each row of B needs to be multiplied with A element-wise.

Homework Equations

Just some basic matrix math.

The Attempt at a Solution

I'm doing this in MATLAB (which does matrix math much faster than loops). I can only think to do a for loop for the number of rows in B, and doing an element-wise multiplication of A and the current row of B. But The number of rows in B is actually quite large and would cause the program to run much slower than I'd like.

 

[mighty2000]

Is there a more efficient way to do this?



Thank you for your post. I understand your concern about the efficiency of your code. In this case, I would recommend using the element-wise multiplication operator in MATLAB, which is represented by the dot '.'. This allows you to perform element-wise multiplication without using a for loop. The code would look something like this:

C = A .* B;

This will multiply each element in A with the corresponding element in B, resulting in a matrix with the same dimensions as B. I hope this helps. Let me know if you have any further questions.