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