Perform Operation on only even rows.

How would I go about performing an operation only on the even rows. For example, you have matrix A and you want to cirshift only the even rows. Thanks

Answer 1

[Azzi Abdelmalek]

A=randi(9,10,4)
idx=2:2:size(A,1);
Ae=A(idx,:)
Ae1=circshift(Ae,[0 -2])
A(idx,:)=Ae1