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