column shuffling of a matrix

Please let me know if i want column shuffling instead of rows what changes i must need in this code.

% for the color image, for even rows and cols
% Need to perform switching of rows at each channel

A = imread('Untitled.png');
[m, n, c] = size(A);
temp= zeros(m,n);
for i = 1 : c
    A1 = A(:, :, i);
    a1 = A1(1 : m/2, :);
    a2 = A1(end: -1 : m/2+1, :);
    temp(1:2:end,:) = a1;
    temp(2:2:end,:) = a2;
    A(:, :, i) = temp;
end

Answer 1

[Andrei Bobrov]

A = imread('Untitled.png');
m = size(A);
out = zeros(m);
m1 = round(m(2)/2);
out(:,1:2:end,:) = A(:,1:m1,:);
out(:,2:2:end,:) = A(:,end:-1:m1+1,:);

Answer 2

[Michael Haderlein]

Please use the {}Code button to make your code readable.

If this code is sorting the rows in the manner you want, you can change it to do the same with columns this way:

A = imread('Untitled.png'); 
[m, n, c] = size(A); 
temp= zeros(m,n); 
for i = 1 : c 
 A1 = A(:, :, i); 
 a1 = A1(:, 1 : n/2); 
 a2 = A1(:, end: -1 : n/2+1); 
 temp(:, 1:2:end) = a1; 
 temp(:, 2:2:end) = a2; 
 A(:, :, i) = temp; 
end