The answer is yes! It is an 1e10 and not 1e-10. At 0.0 you got to pick the interval yourself. You can't just use the starting point x
Date: Wed, 1 Mar 2000 16:06:28 +0100 (MET) From: Fredrik Stenberg <su96-fst@nada.kth.se> To: Hassan Aurag <aurag@CRM.UMontreal.CA> Subject: Re: [Numpy-discussion] Derivatives MIME-Version: 1.0
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?
I tried your algoritm on sin(x) and i got some rather interesting results.
######### EXAMPLE############# from math import sin
def f(x): return sin(x)
import Derivative
print Derivative.Diff(f,0.0)
########RESULT################ -2.03844228853e-10
It should be approx 1.0
I found the error i think.. check row 28 in Derivative h = random()/1e-10 should that be h = random()/1e+10??
Fredrik