Re-ordering / Wrapping pixels

Hi there - I feel like this should be simple but I can't seem to figure it out...

Let's say I have a 16x1 jitter matrix holding 16 values per frame.

How do I wrap them into a 4x4 matrix?

Each line spilling over into the next like this:

1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16

is fine, and I can rearrange positions after that, I guess if I need to... but I can't seem to get this first step.

Thanks!

Hector.