How to shift the vector element inside of the vector?

Is there any fast way I can shift a vector, for example given:

a = [1 2 3 4 5]

How can I shift of two positions the vector in such a way that I get:

a = [0 0 1 2 3]

Thanks.

[Adam]

doc circshift

will do a circular shift, but I'm not aware of a builtin method that will put 0s in the first locations instead so you may have to do that yourself.

Answer 1

[Star Strider]

Another option:

a = [1 2 3 4 5];
as = zeros(size(a));
as(end-2:end) = a(1:3)

as =
     0     0     1     2     3

Answer 2

[Adam]

nShift = 2;

a = circshift( [a zeros(1,nShift )], nShift  );
a = a(1:end-nShift )

will work I guess

Answer 3

[John D'Errico]

I'd just do it in 2 steps.

1. Use circshift.

2. Replace the elements at the beginning with zeros as necessary. If the shift was negative, then replace elements at the end.

So write a little helper function that does this for you, if you will be doing the action often. This is how MATLAB works. If you need something that is not there, then write the tools you need to expand MATLAB in the direction you want it to go.