Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2001
*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 2001

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

Search the Archive

desperate, please help.

  • To: mathgroup at smc.vnet.net
  • Subject: [mg27355] desperate, please help.
  • From: thjqase at aol.com (Thjqase)
  • Date: Wed, 21 Feb 2001 03:18:06 -0500 (EST)
  • Sender: owner-wri-mathgroup at wolfram.com

I need help numerically solving a differential equation coupled with several
algebraic equations. New to Mathematica. Here's code:

NDSolve[{v'[x] == -F÷r, T[x] == 330 + 43.3*x, F = .9*163, C == 9.3, 
    k[x] == 31.1Exp(7906*(T - 360)/(T*360))
    , K[x] == 3.03*Exp(-830.3*((T - 333)/(T*333))), 
    r[x] == -k*C*(1 - (1 + 1/K)*x),
    v[0] == 0}, {v}
  , {x, 0, .7}]

Error code is:

NDSolve::"deql": "The first argument must have both an equation and an \
initial condition."

Any suggestions? What am I doing wrong? My head is sore from banging it against
the wall.

TIA.


  • Prev by Date: Re: page breaks ?
  • Next by Date: Re: Re: Graphing Functions
  • Previous by thread: can not see graphs
  • Next by thread: Re: desperate, please help.