Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2004
*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 2004

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

Search the Archive

Re: numerical solution of an ODE doesn't make sense

  • To: mathgroup at smc.vnet.net
  • Subject: [mg49543] Re: [mg49520] numerical solution of an ODE doesn't make sense
  • From: Selwyn Hollis <sh2.7183 at misspelled.erthlink.net>
  • Date: Fri, 23 Jul 2004 05:59:31 -0400 (EDT)
  • References: <200407220646.CAA21094@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

On Jul 22, 2004, at 2:46 AM, Ita wrote:

> Hello, and thanks in advance to any response.
> I solved a 2nd degree ode with NDSolve for the unknown x(t) for 2 time
> domains: 0<t<100 and 0<t<700, with the same boundary conditions.
> than I ploted the two solutions for 0<t<20, and they came out 
> different ! it
> is like the solution in t<20 is influenced by the solution in t>100 - 
> it
> doesn't make sense.
> thanks,
> Itamar.
>

Most likely it's because of different step sizes. Use the MaxStepSize 
or MaxStepFraction option; e.g., MaxStepSize->1 or 
MaxStepFraction->1/100.

-----
Selwyn Hollis
http://www.appliedsymbols.com
(edit reply-to to reply)


  • Prev by Date: Re: Plotting 2D functions with discontinuities
  • Next by Date: Re: Combining vectors to form a matrix
  • Previous by thread: numerical solution of an ODE doesn't make sense
  • Next by thread: Re: numerical solution of an ODE doesn't make sense