How to sum every elements that have the same frequency?

Suppose I have 2 vectors of the same length.

A = [0.2 0.4 0.8 0.6 1.2 0.3];

B = [ 2 2 1 2 1 1];

The result that I want ---> A+B = [(0.2+0.4+0.6),(0.8+1.2+0.3)].

Please help. Thanks in advance.

Answer 1

[KSSV]

A = [0.2 0.4 0.8 0.6 1.2 0.3];
B = [ 2    2    1    2    1    1];
iwant = [sum(A(B==2)), sum(A(B==1))]

[mrbond99]

It works. Thank you,sir.