Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
1996
*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 1996

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

Search the Archive

Re: Chaotic Equation NDSolve....

  • To: mathgroup at smc.vnet.net
  • Subject: [mg3154] Re: [mg3127] Chaotic Equation NDSolve....
  • From: John Fultz <jfultz>
  • Date: Fri, 9 Feb 1996 03:00:52 -0500
  • Sender: owner-wri-mathgroup at wolfram.com

When doing an NDSolve, all symbols must resolve to numerical values.  In your
case, you had an unresolved symbol f.  If you defined f to be any numerical
example, your NDSolve would work.

Sincerely,

John Fultz
jfultz at wolfram.com
Applications Group
Wolfram Research, Inc.

> Greetings from Mexico City,
> 
> We are a pair of students of chemistry doing some exercises on chaotic systems.
> So we are not too keen on math as a mathematician would be.
> 
> We programmed this system and get this error:
> "Differential Equation does not evaluate as a number at t=1" Tried with 
> different values of t with no success:
> 
> The system we programmed is as follows:
> 
> NDSolve[ {q1'[t] == p1[t],
>           q2'[t] == p2[t],
>           p1'[t] == ((1-f) q1[t])/((1 - q2[t]) ^ 2  + (q1[t]) ^ 2 ) ^ 0.5,
>           p2'[t] == (1-f) - q2[t] - ((1-f) (1-q2[t]))/((1-q2[t]) ^ 2 + (q1[t]) ^ 2) ^ 0.5 ,
> 	  q1 [1] == q2[1] == p1[1] == 1, p2[1] == 2},
>          {p1, q1, p2, q2}, {t, 1, 20}, MaxSteps->3000 ]
> 
> And we dont know what is wrong on it... I hope any one of you can guide/help
> us in our quest of solving this system.
> 
> Thanks a lot in advance.
> 
> Alan Aspuru & Octavio Paniagua...
> 
> Chemistry Faculty,
> Universidad Nacional Autonoma de Mexico


==== [MESSAGE SEPARATOR] ====


  • Prev by Date: Re: os/2
  • Next by Date: Re: Chaotic Equation NDSolve....
  • Previous by thread: Chaotic Equation NDSolve....
  • Next by thread: Re: Chaotic Equation NDSolve....