Multipying each element of a matrix with average of elements in other matrix

I have a 3x3 matrix(A) with all diagonal elements 0, and 3x1 matrix(B). I want to multiply each element of the 3x3 matrix using elements from the 3x1 matrix in the following way: element A(1,2) will be multipled by the average of elements at position 1 and 2 in B.

Similarly each element in A will be multiplied by average of corresponding elements in B.

Is there a way to do this.

Answer 1

[Simon Chan]

Try this:

[Ny,Nx]=size(A);
[X,Y]=meshgrid(1:Nx,1:Ny);
w = (B(X)+B(Y))/2;
C = A.*w

[Hari]

Thanks

Answer 2

[Image Analyst]

Did you try the obvious and simple for loop?

% Create sample data.
A = rand(3);
A(logical(eye(3))) = 0
B = rand(3, 1)
% Now we have our data and can begin...
for col = 1 : 3
	for row = 1 : 3
		factor = mean([B(row), B(col)]);
		A(row, col) = factor * A(row, col);
	end
end
A % Show in command window.

[Hari]

This works. But wouldn't this be slow if the matrix is very large?