Vectorization

Let say I have Matrix M with i rows and j columns. And one constant number a is given. Final output Matrix should be N with rows = i * a and column = j / a, and Each column in N should be concatenation of its a columns. Is it possible to get this without loops ?

For example:

M =

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

N with constant a = 2 should be

N =

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

Answer 1

[G A]

N=reshape(M,j*a,j/a)

Answer 2

[som]

You can write more general code using following code:

N=reshape(M,size(M,1)*a,size(M,2)/a);