Mathematica 9 is now available
Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2012

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

Search the Archive

Re: Parametric List Plot??

  • To: mathgroup at smc.vnet.net
  • Subject: [mg126498] Re: Parametric List Plot??
  • From: Alexei Boulbitch <Alexei.Boulbitch at iee.lu>
  • Date: Tue, 15 May 2012 04:53:15 -0400 (EDT)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com

Hi,
For some phase portraits I want to plot two lists of data in one plot
(x and y axis).
I found ParametricPlot for functions but need that parametric part
combined with ListPlot..?
Thanks in advance!

Hi,
To the best of my knowledge, there is no such a function. There is, however, a simple work around.
Say, for example, you need to solve this:

sol = NDSolve[{y''[t] == Sin[y[t]], y[0] == 1, y'[0] == 0},
   y[t], {t, 0, 3 \[Pi]}][[1]]

{y[t] -> \!\(\*
TagBox[
RowBox[{"InterpolatingFunction", "[",
RowBox[{
RowBox[{"{",
RowBox[{"{",
RowBox[{"0.`", ",", "9.42477796076938`"}], "}"}], "}"}],
        ",", "\<\"<>\"\>"}], "]"}],
False,
Editable->False]\)[t]}

The result is the interpolation function. Now you need a numeric calculus package:

Needs["NumericalCalculus`"]

With this you easily find the numeric derivative, ND[ ], of the solution. Let us package it into a list
With the following structure {...{y[t],y'[t]}...}:

lst = Table[{y[t] /. sol /. t -> t1, ND[(y[t] /. sol), t, t1]}, {t1,
    0, 2. \[Pi], 0.05}];

Here is your phase portrait:

ListPlot[lst]

Evaluate it.

Have fun, Alexei


Alexei BOULBITCH, Dr., habil.
IEE S.A.
ZAE Weiergewan,
11, rue Edmond Reuter,
L-5326 Contern, LUXEMBOURG

Office phone :  +352-2454-2566
Office fax:       +352-2454-3566
mobile phone:  +49 151 52 40 66 44

e-mail: alexei.boulbitch at iee.lu






  • Prev by Date: Re: File size 5.5MB
  • Next by Date: Total least squares with Mathematica?
  • Previous by thread: Re: Parametric List Plot??
  • Next by thread: Re: Parametric List Plot??