shifted triangular matrix array

If I have matrix a=[1 2; 3 4; 5 6; 7 8] (dimension 4x2) and i want to calculate

A= [1 2 0 0 0 0 0 0;

3 4 1 2 0 0 0 0;

5 6 3 4 1 2 0 0;

7 8 5 6 3 4 1 2]

(dimension 4x8),

how can i do?

Thanks.

Answer 1

[Matt J]

ac=num2cell([0,0;a],2); 
T=toeplitz(1:4,[1,zeros(1,3)]);
A=cell2mat(ac(T+1))



A =

     1     2     0     0     0     0     0     0
     3     4     1     2     0     0     0     0
     5     6     3     4     1     2     0     0
     7     8     5     6     3     4     1     2

[JESUS DAVID ARIZA ROYETH]

Excelent!

[Image Analyst]

Jesus, can you "Accept this answer" to give Matt credit for it? Thanks in advance.

[SV]

Amazing! Thank for your help