Set angle to physics angle of motion.

Hi there. So I was wondering about this for a while, how do I set the angle of an object to it's angle of motion?

I have the feeling that it would be:

tan(a) = y/x

∴ tan(velY/velX)^(-1) = a

But that doesn't seem to work very well at all, possibly due to being negative or positive, I'm not sure. There's also the x ≠ 0 problem. I would think then that it would be　tan(abs(velY)/(abs(velX) + 0.0001)) = a　or something but I'm hesitant to try that one out.

I'd rather not learn how to deal with vector, but if it comes to that, oh well.

I think the expression you wanted to do was:

atan(velY/velX) = a

But it will have issues with pos/neg in some quadrants, but fortunately you can just do this:

angle(0,0,velX,velY)

Thanks so much! I'm not entirely sure how, but it works, and it's awesome.