Hi, attached is a file called Derivative.py. It computes derivatives and is based on an algorithm found in Numerical Recipes in C. What to do you think about it and has anyone started a "serious" calculus oriented subpackage for Numerical Python in general? I mean: derivatives, partial derivatives, jacobian, hessian implemented fast and precise. On another note, why isn't infinity defined in NumPy? Why is tan(pi/2) a number even if big? Shouldn't it be infinity?