connecting center points of circles with similar radii

Hi, I have a grid with each point as the center point of a circle with the radius determined by an image that the grid overlays.  I am trying to connect the center points of the circles that have similar radii.  

So far I've been trying to use the center command on the circles and then somehow sorting the list from the radius output to give me only similar values, but cannot for the life of me figure it out.

Thanks

Jake