On the one I built (attached) some of the circles are scaled randomly. Loaded up the version from the book and it works OK. Since some of the circle’s are the correct size and my definition does not any different extra components scaling these objects…I think this is a defect. Circle Attractor.gh (7.2 KB)
It doesn’t look like a defect with GH to me.
Either:
1 Try lifting you point up slightly in the Z direction so that it is not on the XY plane and it works fine.
or
2 Connect the vector output from your vector component to the plane input of the offset component to make the offset component more happy.
Curve offsetting is a fundamentally 2D operation, which means it always works in a specific plane. The default plane for the offset is WorldXY, if you just plug your circular curves into the Plane input of the offset component you’ll perform the offsets within the curve plane, which is what you want in this case.