Re: ListPlot and List problem
- To: mathgroup@smc.vnet.net
- Subject: [mg10889] Re: [mg10814] ListPlot and List problem
- From: jpk@max.mpae.gwdg.de
- Date: Thu, 12 Feb 1998 20:15:21 -0500
Hi Lars,
when You read Your data You get a list
{{phi1,omega1,g1}, {phi2,omega2,g2}, ..}
You Transpose[] is nonsens because it creates a list with
{{phi1,phi2,..},{omega1,omega2,..},{g1,g2,..}}
You need
ListPlot[ myData /. {phi_?NumericQ, omega_?NumericQ, _} :> {omega,phi}]
this is fast and elegant.
If You really want to use Transpose[] You must use it twice
Transpose[
RotateLeft[
Drop[
Transpose[myData], (* { phis, omegas, amps} *)
-1
] (* { phi, omegas } *)
] (* {omegas,phis} *)
] (* {{phi1,omega1},..} *)
The comments after the closing of an command describe how Your data are
looking when the command is complete.
Hope that helps
Jens
> Hi,
>
> I want to plot data that is stored in a file having in the format:
>
> <frequence> <phase> <amplification>
>
> and want to plot the BODE-Diagram. So I did:
>
> myData = ReadList["filename",{Number, Number, Number}];
>
> and now want a plot from <phase> over <frequence> and <amplification>
> over <frequence>I tried things like
>
> ListPlot[Transpose[testData][[3]],PlotJoined->True]
>
> but I always got the wrong list-format. I need
>
> {freqence1,phase1},{freqence2, phase2}...
>
> and I always get things like
>
> {phase1, phase2, phase3} or so.
>
> Can anybody help me a bit?
>
>
> Thanks,
>
> Lars
>