G02 / G02 I and J arguments

Could someone explain to me how the I and J values are used on the circular interpolation commands?

I understand the G02 and G03 commands when using the R "Radius" argument but haven't found a good example of the I and J calculations necessary for arcs. I understand if you need to do a 360 degree circle, in G code you have to split it up into a G02 and then a G03 command.

I'm trying to convert an HPGL AA ( arc absolute ) command to it's G code equivilent. AA gives you X and Y center along with the arc's angle in degrees.

thanks,
Larry E.



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