Thanks for the info, this is getting beyond my knowledge now but I have something that works.
On my Laptop, I am running IDE 2.3.5 and the addition of the Serial.println() , the sine wave starts on 0,0. On my MAC however, running IDE 2.3.6, I still need to set i = -1 to get the sine wave to start at 0,0
Not sure if it’s IDE 2.3.5 vs IDE 2.3.6 or Windows vs MAC OS, I feel I know what the Apple bashers will say though. 