Re: NDSolve and Parametric Plot

*To*: mathgroup at smc.vnet.net*Subject*: [mg85460] Re: NDSolve and Parametric Plot*From*: janos <janostothmeister at gmail.com>*Date*: Mon, 11 Feb 2008 06:11:10 -0500 (EST)*References*: <fomjh1$hmn$1@smc.vnet.net>

On febr. 10, 11:26, Alex Cloninger <aclonin... at wustl.edu> wrote: > So I'm trying to run a simple program that will solve this series of diffe= rential equations and plot the the x[t] function in the complex plane. Here= 's my code. > > solution = NDSolve[{x'[t] == 2p[t], x[0] == 2, p'[t] == -2x[= t], p[0] == Sqrt[-3]}, {x, p}, {t, 0, 2*=F0}] > > repart[t_] := Re[x[t] /. solution] > impart[t_] := Im[x[t] /. solution] > > ParametricPlot[{repart[t], impart[t]}, {t, 0, 2=F0}, PlotRange -> {{-2, 2}= , {-2,2}}] > > For some reason, when I go to plot the curve, I get an error saying > ParametricPlot::pptr: {repart[t], impart[t]} does not evaluate to a pair o= f real numbers at t=2.617993877991494`*^-7 > > What's going on? Could someone please help me with this? Try ParametricPlot[ Evaluate[{repart[t], impart[t]} /. solution], {t, 0, 2 \[Pi]}] Hope, it helps, Janos