Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
1997
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 1997

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

Search the Archive

Mma: Using FindRoot in NonlinearRegress ?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg8749] Mma: Using FindRoot in NonlinearRegress ?
  • From: jost at no-junk-mail.fr (Christian Jost)
  • Date: Sat, 20 Sep 1997 22:28:14 -0400
  • Organization: Universite Paris-Sud XI
  • Sender: owner-wri-mathgroup at wolfram.com

Hello everybody,

I am trying to use the FindRoot function in NonlinearRegress: so far with
no result, but it may be a simple format problem. Has anybody been able to
do this?

Here is a concrete example:
there is some data={{x1,y1},{x2,y2},...}
and some model, say 
y = FindRoot[a x + b Cos[x]==0,{x,{0,10}}][[1,2]]

Now I want to fit a and b to this model:

NonlinearRegress[data,
   FindRoot[a x + b Cos[x]==0,{x,{0,10}}][[1,2]],
   {x},
   {{a,{2.0,1.9},0,Infinity},{b,{0.001,0.002},0,Infinity}},
Method->FindMinimum,
ShowProgress->True,
MaxIterations->20]

But this doesn't work, there is a lot of error output, mainly that
FindRoot didn't find anything. I suspect somehow the current parameters a
and b are not passed to FindRoot. 
Any help will be much appreciated.

Thanks, Christian.

*********************************************************************
Christian Jost, Université Paris-Sud XI, Orsay, France

Please don't send any junk mail or advertisements. For personal mail please send to: Christian.Jost at epc.u-psud.fr


  • Prev by Date: Re: Help! How can I control the size of individual point?
  • Next by Date: Re: Help! How can I control the size of individual point?
  • Previous by thread: Is 3.0.1 worth the upgrade?
  • Next by thread: [Q] error in Integrate