How to shift just the outer loop in an array?

The script should assume an m-by-n array A (m, n >= 2) is assigned in the Command Window. The value mover should also be assigned. The script should rotate all of the values on the outer loop of the array by mover spots clockwise and call the output A_out.

Example executions follow:

>> A = [1 2 3 4 5; 6 7 8 9 10; 11 12 13 14 15; 16 17 18 19 20]; mover = 2;
>> script25_drew_murray

A_out = 
  11     6     1     2     3 
  16     7     8     9     4
  17    12    13    14     5
  18    19    20    15    10

I have written this script so far. I managed to rotate the outer loop according to the mover spots. How do I keep just the middle section of the matrix if this section size is subject to change? Also, how do I put the rotated loop array back in the matrix form given?

dim = size(A);
m = dim(1);
n = dim(2);
B= zeros(m,n)+A

outerloop = [A(1,1:end-1),A(:,n).',A(m,fliplr(1:end-1)),A(fliplr(2:end-1),1).']
rotatedloop = circshift(outerloop,mover,2)

Answer 1

[Andrei Bobrov]

A = [1 2 3 4 5; 6 7 8 9 10; 11 12 13 14 15; 16 17 18 19 20], mover = 2

[m,n] = size(A);
i0 = [(1:m)';(2:n)'*m;m*n - (1:m-1)';(n-2:-1:1)'*m+1];

A = a;
A(i0) = A(circshift(i0,-mover))
A(i0) = A(circshift(i0,mover)) %come back