[Nerdatope]

I still can't quite get the robot to perform correctly. I've manipulated the x and y values the way you both describe, but it has not worked. I've tried everything from changing the angle from positive to negative, phase shifting the angle, swapping the sin and cos, etc.

Here are my symptoms:
What happens at best is the robot will immediately deviate from the direction its told. There appear to be angles at which the drive system will flip, where if the robot is just past the threshold the motors spin one way, but right after the motors spin the opposite way, creating a jittering motion. As time goes on, the joystick values become meaningless as the robot goes a completely irrelevant way in respect to the direction I'm wanting the robot to go.

I thank you for your time spent on this and will post if I figure anything else out.