How to perform this matrix manupulation.?

Hi, I have a row matrix which contains 20 elements ranging from 1 to 20 eg [1,2,3,4...19,20] now i want to arrange the matrix like this [18,19,20,1,2,3,4] in first row in second row [19,20,1,2,3,4,5] in thrid row [20,1,2,3,4,5,6] and so on..means i want to consider 3 elements before the 1 and three elements after the 1 for the first row and same process i have to follow for all the elements...my final matrix will of size 7x20, i want to write this algorithm in MATLAB, Please help me to write this logic. thanks in advance

Answer 1

[Andrei Bobrov]

z = circshift(1:20,[0 3]');
out = hankel(z,rem((z(end):z(end)+6)-1,20)+1);

[harshal j]

thank u so much for the answer ..!!

Answer 2

[Stalin Samuel]

a = 1:20;
n = 7;
A = zeros(n,length(a));
n1 = 3
for it =1:n
A(it,:)= circshift(a',n1)
n1=n1-1;
end

[harshal j]

Thank u sir..!!