- To: mathgroup at smc.vnet.net
- Subject: [mg6964] Re: [mg6911] Help!!!!!!
- From: jpk at max.mpae.gwdg.de
- Date: Wed, 30 Apr 1997 22:25:27 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
> From eguevara at campus.maz.itesm.mx Fri Apr 25 21:43:53 1997 > Date: Fri, 25 Apr 1997 14:00:40 -0400 (EDT) > From: Eusebio Guevara Villegas <eguevara at campus.maz.itesm.mx> > To: mathgroup at smc.vnet.net > Subject: [mg6911] Help!!!!!! > > I integrated the following equation: (e^(x^2)) with mathematica, and it > give me the following result: (Sqrt[Pi] Erfi[x])/2. My question is: What > the Erfi means...... I consult the kernel help and it is about Gaussian > Distribution, but I don't know what it is? > > Thanks for your help. > Sinceresly > Gustavo Lozano Ibarra > al540562 at campus.maz.itesm.mx > Hi Gustavo, consult one of the standard books on special functions like Abramowitz/Stegun. You will find that one of the possible definitions of the Erfi-Function is Erfi[x]=2*Integrate[Exp[x^2],x]/Sqrt[Pi] or Erf[I*z]/I -- so here is the answer: Erfi is a function that is defined by a infinite series (like Exp, Sin,..) and/or just by the integral above. Hope that helps Jens