MathGroup Archive 2005

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

Search the Archive

Re: fourier transform

  • To: mathgroup at
  • Subject: [mg61214] Re: fourier transform
  • From: Torsten Coym <torsten.coym at>
  • Date: Thu, 13 Oct 2005 01:39:25 -0400 (EDT)
  • Organization: Fraunhofer Gesellschaft (
  • References: <dii9qs$9q1$>
  • Sender: owner-wri-mathgroup at

Take a look at Mathematica's help: Fourier[data] expects data to be a
list of complex numbers, not pairs of time and amplitude.

I assume that your list is equally spaced in time -- only then a
application of Fourier[] would lead to useful results.

Get rid of the timing information in your data, by replacing every pair
of {time,amplitude} with the amplitude only.



Have a look at Chop[] to suppress small imaginery parts that come from
the numerical process.


Masrur Hossain wrote:
> Hi folks
>            I have a list of pairs of numbers like
>   {{1.2, 3.4}, {2.2, 3.6}............}
> The first part is time and second part is amplitude.
> when I do the fourier transform by using
> Fourier[list]
> it gives me list of complex numbers but I expect real numbers
> (i.e . amplitude versus frequency)
> Any help appreciated.
> thanks

  • Prev by Date: Re: Element test
  • Next by Date: Re: Element test
  • Previous by thread: Re: fourier transform
  • Next by thread: NET/Link with Mono?