I have obtained few matrices by `for`-loop.  

Say for example `m1(for i=1)=[1 ; 2 ; 3]`, `m2(for i=2)=[4 ;5 ; 6]`, `m3(for i=3)=[7; 8 ; 9]` and so on.  

Now I want to form a bigger matrix, `M`, from the elements of `m1`, `m2`, `m3` and so on: 

```
M=[0 0 0 1 - - ;
   0 1 4 7 - - ;
   0 2 5 8 - - ;
   0 3 6 9 - - ;
   0 0 0 0 - - ]  

```

`M` is a very big dimension (`m x n`) matrix and each column of `M` represents a `mi` matrix and some of its specific column will be `zero` (null matrix).  

How can I efficiently achieve this?