How do you verify the outcome? The goal is to get a circumventing circle with minimal radius around all packed non-overlapping sample circles?
I mean the 10 circle solution (above) looks like the minimal radius found could yet decrease if only the yellow marked circles moved towards the center and the two small circles near the center moved outward to the boundary somewhere between bigger ones?
Have you tried the algorithm with a set of sample circles known to fit into a circumventing circle, like
the delta is only a visual guess, I did not compute that to reach a match.
