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Re: Discrete Fourier Transform

• To: mathgroup at smc.vnet.net
• Subject: [mg109688] Re: Discrete Fourier Transform
• From: "Nasser M. Abbasi" <nma at 12000.org>
• Date: Wed, 12 May 2010 07:32:34 -0400 (EDT)
• References: <hsbb96$jdt$1@smc.vnet.net>

"Jim Lambaugh" <lambaugh at gmail.com> wrote in message 
news:hsbb96$jdt$1 at smc.vnet.net...
> Hi guys
>
> I have a function f(x), and I need to find its discrete Fourier
> transform. I have taken a look at 
> http://reference.wolfram.com/mathematica/tutorial/FourierTransforms.html,
> but it only returns the amplitude of the FT. - not the phase factor.
> Which command do I have to use in order to get the phase factor as
> well?
>
> Best,
> Jim.
>

DFT takes as input a list of numbers (not a function f(x))  and returns a 
list of numbers.

DFT does not return "just the amplitude of the FT", where does it say that? 
in the documentation? if it does, need to report it to WRI because that 
would be an error in documentation.

To find the "amplitude" of a complex number v, use the command Abs[v], to 
find its "phase", use Arg[v]

--Nasser