Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2006
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2006

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: FoourierTransform of a function defined in sections

  • To: mathgroup at smc.vnet.net
  • Subject: [mg70217] Re: FoourierTransform of a function defined in sections
  • From: Bill Rowe <readnewsciv at sbcglobal.net>
  • Date: Sat, 7 Oct 2006 07:08:54 -0400 (EDT)

On 10/6/06 at 1:59 AM, e.schlemm at hotmail.de (Eckhard Schlemm) wrote:

>I want Mathematica to calculate the FourierTransform of a function
>which is defined by Sin[x]^2 for Abs[x]<PI and zero else. I tried
>and defined the function g as follows:

>g[x_]:=If[Abs[x]>PI,0,Sin[x]^2];

>That works fine. But if I have mathematica try to determine the
>FourierTransform by

>FourierTransform[g[x],x,p]

>I always get the error that the recursion limit and the iteration
>limit were exceeded...

Try defining g in terms of UnitStep, i.e.,

In[10]:=
g=Sin[x^2](UnitStep[x+Ï?]-UnitStep[x-Ï?]);
FourierTransform[g,x,w]

Out[11]=
(1/2)*(Cos[w^2/4]*(FresnelS[(2*Pi - w)/Sqrt[2*Pi]] +
      FresnelS[(w + 2*Pi)/Sqrt[2*Pi]]) -
    (FresnelC[(2*Pi - w)/Sqrt[2*Pi]] + FresnelC[(w + 2*Pi)/Sqrt[2*Pi]])*
     Sin[w^2/4])
--
To reply via email subtract one hundred and four


  • Prev by Date: Re: Exporting EPS figures
  • Next by Date: Re: List manipulation
  • Previous by thread: Re: FoourierTransform of a function defined in sections
  • Next by thread: Re: FoourierTransform of a function defined in sections