Re: Fourier Transform Graph Coordinates
- To: mathgroup at smc.vnet.net
- Subject: [mg95053] Re: Fourier Transform Graph Coordinates
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Sun, 4 Jan 2009 07:34:43 -0500 (EST)
- References: <gjng7r$2mm$1@smc.vnet.net>
Hi,
what is with
lst=MapIndexed[{#2[[1]], #1} & ,
Abs[Fourier[{-1, -1, -1, -1, 1, 1, 1, 1}]]]
Grid[Prepend[lst, {"X", "Y"}]]
??
Regards
Jens
DAVID FOURIE wrote:
> Hi all,
>
> I am wanting to compare Fourier Transform graphs in a Java Program. For thi=
> s I need the coordinates, or graph points of the created Fourier Transform =
> graph.
>
> For example using the Mathematica example:
>
> In[]:= Fourier[{-1,-1,-1,-1,1,1,1,1}]
> Out[]:= {0.\[InvisibleSpace] + 0. \[ImaginaryI], -0.707107 - 1.70=
> 711 \[ImaginaryI], 0.\[InvisibleSpace] + 0. \[ImaginaryI], -0.707107 - 0.29=
> 2893 \[ImaginaryI], 0.\[InvisibleSpace] + 0. [ImaginaryI], -0.707107 + 0.29=
> 2893 \[ImaginaryI], 0.\[InvisibleSpace] + 0. \[ImaginaryI], -0.707107 + 1.7=
> 0711 \[ImaginaryI]}
>
> In[]:= ListPlot[Abs[Fourier[{-1, -1, -1, -1, 1, 1, 1, 1}]],
> Out[]:= A zig zag graph.
>
>
> I want the coordinates of this graph. I have tried exporting it as a table =
> but it is indecipherable. Idealy the graph would be in the style:
> X Y
> 1 10
> 2 23
> 3 24
> 4 27
> 5 31
>
> Etc
>
> The style is not the concern though it is just getting the data which gener=
> ates the graph.
>
> Yours
>
>
>
> David Fourie BSc Computer Science
> David.fourie at ncl.ac.uk
> MPhil Computational Neuroscience
> D809
> ext - 8593
>