How to make a slide windows?

Please help me out!

A = [ 1 2 3 4 5 6; 7 8 9 10 11 12 ; 13 14 15 16 17 18 ];

A =

     1     2     3     4     5     6
     7     8     9    10    11    12
    13    14    15    16    17    18

B=[ 1 7 13 0 0 0 0 0; 0 2 8 14 0 0 0 0; 0 0 3 9 15 0 0 0 ; 0 0 0 4 10 16 0 0; 0 0 0 0 5 11 17 0; 0 0 0 0 0 6 12 18];

B =

     1     7    13     0     0     0     0     0
     0     2     8    14     0     0     0     0
     0     0     3     9    15     0     0     0
     0     0     0     4    10    16     0     0
     0     0     0     0     5    11    17     0
     0     0     0     0     0     6    12    18

Could I make this B matrix without for loop condition?

Please help me out!

Answer 1

[Azzi Abdelmalek]

A = [ 1 2 3 4 5 6; 7 8 9 10 11 12 ; 13 14 15 16 17 18 ]
[n,m]=size(A)
B=[A' zeros(m,m-1)]
D=cell2mat(arrayfun(@(x) circshift(B(x,:),[0 x-1]),(1:m)','un',0))

[HYUNCHUL]

Thank you so much for your help!

Answer 2

[Walter Roberson]

See the Example in http://www.mathworks.com/help/matlab/ref/diag.html for an example of filling the supra and super diagonal. You want k = 0, k = 1, k = 2