Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2005
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2005

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

Search the Archive

Re: NDSolve and differential equation system

  • To: mathgroup at smc.vnet.net
  • Subject: [mg54057] Re: NDSolve and differential equation system
  • From: Christian Moosmann <some@Adress>
  • Date: Wed, 9 Feb 2005 09:27:31 -0500 (EST)
  • Organization: Rechenzentrum der Universitaet Freiburg, Germany
  • References: <cu1vjh$ltj$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Hi again

Thanks for your suggestions, using Erf[] instead of UnitStep[] gains a 
factor of about 2, so this is a step to the right direction.


 > You can a) use the wonderful advanced interface of NDSolve[]
 > to use a constant step size

Sadly the IDA method does not support fixed step sizes. And - correct me 
if I am wrong - only the IDA method can solve differential algebraic 
equations.

 > However, if Ainv.K1 and Ainv.K2 commute

Thanks for your effort here, but sadly they don't :-(




Thanks again very much for your suggestions. Do you have some more?  ;-)

Christian


  • Prev by Date: Re: Nonlinear Fittings: range / boundaries are not working :(
  • Next by Date: Re: Fourier function...having problems reproducing answers in a paper
  • Previous by thread: Re: NDSolve and differential equation system
  • Next by thread: Re: NDSolve and differential equation system