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

Help on solving simultaneous non-linear equations using FindRoot.

  • To: mathgroup at smc.vnet.net
  • Subject: [mg28514] Help on solving simultaneous non-linear equations using FindRoot.
  • From: Youyan Li <youyanli at acsu.buffalo.edu>
  • Date: Tue, 24 Apr 2001 01:48:50 -0400 (EDT)
  • Organization: University at Buffalo
  • Sender: owner-wri-mathgroup at wolfram.com

Hi,

I am trying to solve a 12-eqaution simultaneous non-linear equations using
FindRoot function in Mathematica. This system of equations has 9 given  
parameter values and I need to solve for 12 unknown variables. But I have
the problem in getting the system converged. If I take one endogenous   
variable out of the system and let it to be a given parameter, and also
reduce the system into 9 equations, I can get a solution that looks like
converged, but some of the variables have negative values, which are not
what I expected. I expect all the variables have non-negative values.
If I specify the range of the variables, usually I cannot get a solution  
at all. I wonder how to solve this problem. Or how to get an acceptable  
solution for this system? Is there any trick of solving large system of  
simultaneous non-linear equations using FindRoot? Thank you for the help
in advance.

Youyan Li



  • Prev by Date: Re: ListPlot with row vectors
  • Next by Date: Re: ListPlot with row vectors
  • Previous by thread: Help on solving simultaneous non-linear equations using FindRoot.
  • Next by thread: Re: Help on solving simultaneous non-linear equations using FindRoot.