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Fourier Transform Bug

  • To: mathgroup at smc.vnet.net
  • Subject: [mg63604] Fourier Transform Bug
  • From: "irchans" <infinitgames at yahoo.com>
  • Date: Sat, 7 Jan 2006 02:29:27 -0500 (EST)
  • Sender: owner-wri-mathgroup at wolfram.com

The fourier transform for mathematica version 5.0 does not seem get the
correct result when using FourierParameters with the product of x and
Exp[-x^2].   According to the documentation, the following ratio should
always be 1/ Sqrt[2 Pi].

checkratio[f_] := FourierTransform[ f[x], x, y, FourierParameters ->
{0, -2 Pi}]/
    FourierTransform[  f[x], x, y, FourierParameters -> {1, -2 Pi}];

In fact, the following expressions correctly evaluate to 1/ Sqrt[ 2
Pi]:

checkratio[# &]
checkratio[#^2 &]
checkratio[Exp[-#^2] & ]
checkratio[DiracDelta]

But,

checkratio[#*Exp[-#^2] & ]

evaluates to 1/ 2/Pi which is incorrect.  Can anyone else repoduce this
bug?


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