Custom math functions vs. supplied Math functions?

Question

I am basically making a Java program that will have to run a lot of calculations pretty quickly(each frame, aiming for at least 30 f/s). These will mostly be trigonometric and p

Answer 1

If you can bear 1e-15ish relative error (or more like 1e-13ish for pow(double,double)), you can try this, which should be faster than java.lang.Math if you call it a lot : http://sourceforge.net/projects/jafama/

As some said, it's usually hard to beat java.lang.Math in pure Java if you want to keep similar (1-ulp-ish) accuracy, but a little bit less accuracy in double precision is often totally bearable (and still much more accurate than what you would have when computing with floats), and can allow for some noticeable speed-up.