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NDSolve and Parametric Plot

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  • Subject: [mg85430] NDSolve and Parametric Plot
  • From: Alex Cloninger <acloninger at>
  • Date: Sun, 10 Feb 2008 05:17:48 -0500 (EST)

So I'm trying to run a simple program that will solve this series of differential 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*Ï?}]

repart[t_] := Re[x[t] /. solution]
impart[t_] := Im[x[t] /. solution]

ParametricPlot[{repart[t], impart[t]}, {t, 0, 2Ï?}, 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 of real numbers at t=2.617993877991494`*^-7

What's going on?  Could someone please help me with this?

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