Computational problem

Hi

this is a semplification of my problem. I have 2 matrix

 A=(1:1:4)';

 B=(10:10:120)';

and I need to define a new matrix (column vector) C that is composed by 12 elements. The first 3 elements are the first term of A, the seconds 3 elements are the second term of A, and so on. In this case C=[1 1 1 2 2 2 3 3 3 4 4 4]' How could I do? take in consideration that in reality I cant define a new matrix. The real problem is:

 T=1200;
 n=6
 m=5
 g=m*n
 p = 2:(n-1);
 for  j1 = numel(p):-1:1
     cc(:,j1) = (2+(m*(p(j1)-1))):1:(m*p(j1)-1);
 end
 cc = cc(:).';

 ((2.718.^(-(m-rem(cc,m)-1)))')  .*  (T^4-(x(p*m+g).^4))';
           i.e. B                         i.e. A

the first part is a column vector of 12 elements and the second part is a column vector of 4 elements. (the term (x(p*m+g) is part of a column vector and is composed of 4 elements). So I need to get a column vector of 12 elemets from the second part of the code without define a new matrix and it must be define as C. Help me!!!

Answer 1

[Walter Roberson]

For the first part of the question, the solution is

C = kron(A, ones(3,1));

Answer 2

[Jonathan Sullivan]

You might not need to. It sounds like bsxfun would help you out. You essencially want to multiply every element of vector A with every element of vector B.

Check this out.

A=(1:1:4);     % row vector
B=(10:10:120)'; % column vector
C = bsxfun(@times,A,B) % matrix