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Re: Q: how to start Solve[] with an initial solution guess?


  • To: mathgroup@smc.vnet.net
  • Subject: [mg12462] Re: Q: how to start Solve[] with an initial solution guess?
  • From: Paul Abbott <paul@physics.uwa.edu.au>
  • Date: Tue, 19 May 1998 13:31:30 -0400
  • Organization: University of Western Australia
  • References: <6jf6bv$4ai@smc.vnet.net>

Bill Christens-Barry wrote:
 
> I have a system of equations that Mathematica 3.0 bogs down on for most
> problems of interest.  I would like to seed a solution that is found
> for one set of parameters into the routine for finding the solution of
> a "nearby" problem (meaning one with only slightly different parameter
> values).
> 
> How can I do this?  

Sounds like a perturbation problem -- and Series methods might be
useful.

> I have tried including a set of conditions (bounds)
> on the solution space as inequalities in the system of equations to be
> solved, but Mathematica gagged on the form of the inequalities.
> 
> Are there other methods of launching Solve[] from an initial trial
> solution?

Well, you can certainly pass an initial guess to FindRoot -- which, in
many cases is more appropriate than trying to use Solve anyway.
 
> Should I be trying to learn how to instruct Solve[] on what methods it
> should be using?  If so, where can I learn about this?
> 
> Examples that illustrate any explanation would be especially helpful.

An example of the problem you are trying to solve would be especially
helpful.

Cheers,
	Paul 

____________________________________________________________________ 
Paul Abbott                                   Phone: +61-8-9380-2734
Department of Physics                           Fax: +61-8-9380-1014
The University of Western Australia            Nedlands WA  6907       
mailto:paul@physics.uwa.edu.au  AUSTRALIA                            
http://www.pd.uwa.edu.au/~paul

            God IS a weakly left-handed dice player
____________________________________________________________________



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