Need for explication of this code

I need explication of this code

V=(1:50);
 I=3; 
J=4;
 M=[];
 for i=1:J:I*J
    M=[M;V(i:i+I)]; 
end;

[Ruger28]

This "code" isn't even finished...

[Alex Mcaulley]

Put a breakpoint in this line:

M=[M;V(i:i+I)]; 

and see what is happening in each iteration

Answer 1

[CAM]

"i" starts with 1. M becomes [V(1:(1+3))] = [1:4] = [1 2 3 4].

"i" becomes 5 = (1+J) = (1+4). M adds a row with [5 6 7 8]. Etc...

Ultimately, this will give you the numbers 1 through 12 in a 4x3 matrix.

1 2 3 4

5 6 7 8

9 10 11 12

Why use all that code when you could use: M=reshape([1:12], 4,3) ?