Re: Defining Real expressions
- To: mathgroup at smc.vnet.net
- Subject: [mg8509] Re: Defining Real expressions
- From: hans.steffani at e-technik.tu-chemnitz.de (Hans Steffani)
- Date: Thu, 4 Sep 1997 02:19:55 -0400
- Organization: University of Technology Chemnitz, FRG
- Sender: owner-wri-mathgroup at wolfram.com
Marco Beleggia <beleggia at gpxbof.df.unibo.it> writes:
>I must evaluate an Integral in which I'd like to assign real values to
>some parameters, but I don't know how to do that.
>For example, in the following integral (a Fourier Transform):
>f[x_,p_]=Integrate[y/(x^2+y^2) Exp[-I p y],{y,-Infinity,Infinity}],
>p should be a real parameter. The output given by Mathematica is
>conditioned to Im[p]==0, such as If[Im[p]==0,....,....], which is not
>easy to handle, and I'd like to avoid this complication.
I do not understand the problem:
Integrate[y/(x^2+y^2) Exp[-I p y],{y,-Infinity,Infinity}]
delivers
2
2 1/4 Sqrt[p ] Pi
-I (p ) Sqrt[Pi] Sqrt[-----------]
2
p
-------------------------------------
2 2
Sqrt[p ] Sqrt[x ]
E
Maybe ComplexExpand[] helps in your case.
h.f.s.
[cc,fup]
--
Hans Friedrich Steffani
Institut fuer Elektrische Maschinen und Antriebe, TU Chemnitz-Zwickau
mailto:hans.steffani at e-technik.tu-chemnitz.de
http://www.tu-chemnitz.de/~hfst/