matrix convertion and reconvertion

 I want to move the matrix elements as desired like

a=[1 2 3 4;

 5 6 7 8;

 9 10 11 12;

 13 14 15 16]

now i want to make a into b

b=[3 4 8 7;

 11 12 16 15;

 14 13 9 10;

 6 5 1 2]

how can i do it in MATLAB and how can i convert b back into a?

[Azzi Abdelmalek]

Duplicate at

http://www.mathworks.com/matlabcentral/answers/116820-matrix-elements-movement-in-matlab

Answer 1

[David Young]

To convert a into b, you can write

b(1,1) = a(1,3);
b(2,1) = a(3,3);
...

and so on. To convert back, use

a(1,3) = b(1,1);
a(3,3) = b(2,1);
...

and so on.

I suspect that perhaps you want something more concise. If so, please explain the rule that you are using, as I can't reliably infer it from the example.

Answer 2

[Azzi Abdelmalek]

a=[1 2 3 4;
  5 6 7 8;
  9 10 11 12;
  13 14 15 16]
b=a(:,3:4);
c=a(:,1:2);
b(2:2:end,:)=fliplr(b(2:2:end,:));
c=flipud(c);
c(1:2:end,:)=fliplr(c(1:2:end,:));
d=[b' c'];
out=reshape(d(:),size(a,2),[])'