Image_sampler_Circles

I am trying to do this
http://www.grasshopper3d.com/photo/photo/show?id=2985220:Photo:30047
I got the definition from Leonid Krykhtin on November 29, 2009 at 6:44am Portrait.ghx
I have made a post there
But for some reason is not working...all my circles are the same radius!
please help me out