Thanks, purplewind and Gaieus.
I often use 'Point at Center' in context menu, since I'm piping designer. That because I hardly use 'weld.rb' and I often use 'clf_arc_centerpoint_finder.rb', 'centerpoint.rb' and 'nilines2arc.rb'. If the circle function can specify its normal vector via drag as the rotate function, then I don't need 'nilines2arc.rb'.

Oops! I hesitate this is on top topic, since this script has many lines that 'Exploded arc centerpoint finder' Chris wrote.

I use many tiny scripts that I wrote. That's why I use submenu. It's only for me. You may change lines of this script for menu placing as Ken did.

Thanks Ken and Jim.

I create a script that converts lines (exploded arc curve) to an arc curve.
It also can convert offseted arc and followmeed arc.

Special thanks to Chris Fullmer! You may take, rebuild and release this as yours.

nilines2arc.rb

Thanks Chris!

I'll make a script that changes exploaded edges to an arc curve.
Yours is very helpful for me.

note: line 42 does not check that both of two selected entities are edges. It checks only one.

Thank you.