Register to reply 
Calculating erf(x)?by LM741
Tags: erfx 
Share this thread: 
#1
Aug1006, 11:40 AM

P: 130

Hi guys...
don't suppose anybody knows how to calculate the error function  erf(x) I know Matlab can calculate it  but is it possible to evaluate it without computational techniques (i.e. using computers)? [tex] {erf}(x) = \frac{2}{\sqrt{\pi}}\int_0^x e^{t^2} dt.[/tex] Would appreciate any feedback. thanks. The link below will direct you to a website where the equation can be viewed... http://images.planetmath.org:8080/ca...9/l2h/img2.png 


#2
Aug1006, 03:21 PM

Math
Emeritus
Sci Advisor
Thanks
PF Gold
P: 39,497

If you mean "Is there an elementary antiderivative" that can be evaluated directly, the answer is no. The only way to evaluate erf(x) is to do a numerical integration.



#3
Aug1006, 04:32 PM

P: 130

thanks...
by numerical integration do you mean applying Tayler Series and expansions like that? 


#4
Aug1006, 08:17 PM

Math
Emeritus
Sci Advisor
Thanks
PF Gold
P: 39,497

Calculating erf(x)?
I was thinking more of Simpson's rule.



#5
Aug1006, 09:35 PM

P: 2,251

see http://mathworld.wolfram.com/Erf.html for some detail. 


#6
Aug1106, 08:43 AM

P: 130

thanks guys!



Register to reply 
Related Discussions  
Calculating A in SHM from x, v & a  Introductory Physics Homework  12  
Calculating Rv  Introductory Physics Homework  7  
Calculating Ka  Biology, Chemistry & Other Homework  2  
Calculating dd.mm.ss  Calculus  1 