Mathematica 9 is now available
Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2007

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

Search the Archive

Solving stiff differential equations

  • To: mathgroup at smc.vnet.net
  • Subject: [mg84490] Solving stiff differential equations
  • From: dkjk at bigpond.net.au
  • Date: Sat, 29 Dec 2007 02:58:31 -0500 (EST)

Hi all,

I want to solve the following nonlinear ODE

x'[t] == M - 3 x[t] Sqrt[-M*t + 7/10 + x[t]]

x[0] == 3/10

where M is a very large number (~10^43).

I tried solving this using

M = 10^43;
s = NDSolve[{x'[t] == M - 3 x[t] Sqrt[-M t + 7/10 + x[t]],
   x[0] == 3/10}, x[t], {t, -10, 10}, WorkingPrecision -> 20]
Plot[Evaluate[x[t] /. s], {t, -10, 10}, PlotRange -> All]

but I got a lot of errors.  Could anyone please advise how I should go
about solving this?

Best regards,
James


  • Prev by Date: Re: Timing and Pi
  • Next by Date: help with mathematica 5.2-Vector
  • Previous by thread: Re: Compiling Random Numbers from a distribution
  • Next by thread: Re: Solving stiff differential equations