@Kitonum Perhaps to better explain my quandry, I have two different pipes, where I measure the radius at 1/3 degree intervals around the entire internal diameter.  Because I can not be certain that the centre of the pipe is used for each pipe measurement, I would like to be able to vary to origin of one pipe relative to the other, then perform a check to see if the line-up between the two circumferences is better or not.

So basically I want to be able to translate the origin of the prescribed circle, then calculate the new radius measurements based on the original origin point.

best regards

Andrew