Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2007
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2007

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

Search the Archive

numerical_solution

  • To: mathgroup at smc.vnet.net
  • Subject: [mg73354] numerical_solution
  • From: "j. r. campanha" <campanha at rc.unesp.br>
  • Date: Tue, 13 Feb 2007 07:02:59 -0500 (EST)

Dear MathGroup people


How can I know which is the best numerical solution?


w == 6;
A == 0.1;
B == 0.17;
F == 0.501;

solution1 == NDSolve[{x'[t] ==== v[t], v'[t] ==== -(B)*(v[t]) - (A)*(((x[t]=
))/(1 - (x[t])^2)) + (F)*(Cos[w*t]),x[0] ==== 0.4, v[0] ==== 0.3}, {x, v}, =
{t, 260, 270}];

ParametricPlot[Evaluate[{x[t], v[t]} /. solution1], {t, 260, 270}, Frame ->=
 True]


OR

solution2 == NDSolve[{x'[t] ==== v[t], v'[t] ==== -(B)*(v[t]) - (A)*(((x[t]=
))/(1 - (x[t])^2)) + (F)*(Cos[w*t]),x[0] ==== 0.4, v[0] ==== 0.3}, {x, v}, =
{t, 260, 270}, Method -> StiffnessSwitching];


ParametricPlot[Evaluate[{x[t], v[t]} /. solution2], {t, 260, 270}, Frame ->=
 True]



Jose R. Campanha
UNESP-Physics Dpto
Rio Claro - S=E3o Paulo
Brasil



  • Prev by Date: Re: RandomArray from user defined distribution?
  • Next by Date: Re: Curve-fitting/data analysis question...
  • Previous by thread: Re: Writing to an external file?
  • Next by thread: Re: numerical_solution