How to multiply a matrix by certain numbers?

I want to multiply a matrix by a column vector in this way:

(4 2 3 8;7 9 1 5;6 4 8 3) * (4;8;2)

and then the result i want to get is:

(4*4 2*4 3*4 8*4;7*8 9*8 1*8 5*8;6*2 4*2 8*2 3*2)

[Shubha Baravani]

If x=(1 2 3 4) And if y=(2 3 4 5) How can I multiply each sample of x by each sample of y so that I get the output as Z=(2 3 4 5 4 6 8 10 6 9 12 15 8 12 16 20)

[madhan ravi]

xy = repmat(x,1,1,numel(x)) .* reshape(y,1,1,[]); % for version <=2016b bsxfun(@times,repmat(x,1,1,numel(x)) , reshape(y,1,1,[]))
Wanted = reshape(squeeze(xy).',1,[])

[Stephen23]

@Shubha Baravani: the simple MATLAB way:

>> x = [1,2,3,4];
>> y = [2,3,4,5];
>> z = kron(x,y)
z =
    2    3    4    5    4    6    8   10    6    9   12   15    8   12   16   20

Answer 1

[Stalin Samuel]

A = [4 2 3 8;7 9 1 5;6 4 8 3];
B = [4;8;2]
for i = 1:length(B)
C(i,:) = A(i,:)*B(i)
end

[Stephen23]

Note that:

1. The array C expands on every iteration, which is slow and inefficient. Preallcoation would resolve this.
2. Using a loop is more complex than using vectorized code.
3. The variable name i should be avoided, as it is the name of the imaginary unit.

Answer 2

[Stephen23]

Just use bsxfun:

>> X = [4 2 3 8;7 9 1 5;6 4 8 3];
>> Y = [4;8;2];
>> bsxfun(@times,X,Y)
ans =

     16    8   12   32
     56   72    8   40
     12    8   16    6

[Royvg94]

This one is much better, thanks! But i cant change my accepted answer right?