
#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: 38,879

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: 38,879

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




#5
Aug1006, 09:35 PM

P: 2,265

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



#6
Aug1106, 08:43 AM

P: 130

thanks guys!



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