Code reference
I, J, K vs R in G02: Arc Center Words Explained
I, J, and K give the arc center as an offset from the start point, while R gives the radius. Here is when each works, and why full circles need I and J.
Lawrence Arya··5 min
Code reference
How to Calculate I and J for a G02 Arc (Worked Examples)
I and J are the distance from the arc's start point to its center: I = center X minus start X, J = center Y minus start Y. Two worked examples and a self-check.
Lawrence Arya··5 min