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Re: Fourier Transform

• To: mathgroup at smc.vnet.net
• Subject: [mg124261] Re: Fourier Transform
• From: Murray Eisenberg <murray at math.umass.edu>
• Date: Sat, 14 Jan 2012 17:14:55 -0500 (EST)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• References: <201201140756.CAA01348@smc.vnet.net>
• Reply-to: murray at math.umass.edu

ARe you using Mathematica 8 (8.0.4) and did you forget to type 'Abs', 
with an upper-case letter?

I get:

   FourierTransform[HeavisideTheta[a - Abs[t]], t, w,
   Assumptions -> a > 0] // InputForm
((-I)*(-1 + E^((2*I)*a*w)))/(E^(I*a*w)*Sqrt[2*Pi]*w)


On 1/14/12 2:56 AM, jstorch at earthlink.net wrote:
> Mathematica hangs when trying to evaluate the simple Fourier Transform
> of H(a-|t|).
>
> FourierTransform[HeavisideTheta[a-abs[t]],t,w,Assumptions->a>0]
>
> (The answer should be Sqrt(2/Pi) (Sin[w a])/w  )
>

-- 
Murray Eisenberg                     murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower      phone 413 549-1020 (H)
University of Massachusetts                413 545-2859 (W)
710 North Pleasant Street            fax   413 545-1801
Amherst, MA 01003-9305

• References:
  • Fourier Transform
    • From: jstorch@earthlink.net