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 >