Services & ResourcesWolfram ForumsMathGroup Archive

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

NDSolve help

• To: mathgroup at smc.vnet.net
• Subject: [mg43626] NDSolve help
• From: sashan <mabus at operamail.com>
• Date: Fri, 26 Sep 2003 04:45:38 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

I'm a newb to mathematica. I'm trying to use NDSolve for a system of 2 
2nd order ODE's and it complains that the number of initial conditions 
(4) is not equal to the total order of the system (2). But I'm pretty 
sure I've specified all the initial conditions. I've pasted the NDSolve 
code I'm trying to write.

\!\(\(solution\  = \ NDSolve[{\(y''\)[t] == \(-\((\(-\ x[
        t]^2\) + y[t]\ v^2)\)\), \ \(x''\)[
                t] == \(-\((\ x[t] y[t] + x[t] v^2)\)\),
                     y[0] == 0, \(y'\)[0] == \(-1\), x[
            0] == 1, \(x'\)[0] == 0} /.
              v -> \@\(\(x'\)[t]^2 + \(y'\)[t]^2\), {x, y}, {t, 0, 
200}];\)\)

Thanks

• Follow-Ups:
  • Re: NDSolve help
    • From: Michael Williams <williams@vt.edu>