Question

I have a matrix in Matlab, A =

 1     2     3
 4     5     6
 7     8     9
10    11    12

Now I want to create a new matrix B derived from A. The new matrix should look like: B =

1   0
0   4
2   0
0   5
3   0
0   6

Is it possible to solve that without using FOR loop?

Answer 1

Easy with some indexing:

A=[1     2     3  ;
   4     5     6  ;
   7     8     9  ;
   10    11    12 ];

B = zeros(2*size(A,2),2);
B(1:2:end,1)=A(1,:); % put first row values in first column of c
B(2:2:end,2)=A(2,:); % put énd row values in 2nd column of c