Re: Trouble with fsolve

[David Bateman]

Joel Konkle-Parker wrote:

> On Tue, 2005-10-18 at 17:17 +0200, David Bateman wrote:
>  
>
> > together with the explanation of why this is the wrong way to go.. Note 
> > that the changes to "quad" were made. However daspk, dasrt, dassl, 
> > fsolve, lsode and odessa weren't converted as the resulting code is an 
> > ugly hack. The only real solution is to completely dump the existing 
> > mess for these functions and reimplement it removing the underlying 
> > fortran code.... So a workaround with global variables is the only way 
> > this can be done at the moment in octave..
> >    
>
> Have you guys looked at SciPy for an example? Their fsolve function lets
> you include multiple parameters, and according to them, it's just a
> simple wrapper around MINPACK.
>
> http://www.scipy.org/documentation/apidocs/scipy/scipy.optimize.minpack.html#-fsolve
>
>
>  
Octave also uses minpack for fsolve. The issue I had was not one of 
multiple arguments per-se, but how to define a single function in the 
same manner as matlab that returns both the function evaluations and the 
jacobian. The underlying fortran code wants two seperate functions. 
Given permission to be completely matlab incompatiable and allow 
multiple argument function handles to be passed to fsolve, etc and force 
the user to define the function and its jacobian seperately then yes 
something can be done. If you want a completely matlab compatiable 
fsolve that calculates the function and the jacobian in a single 
function, without the mess of caching the results, then you have to 
rewrite the underlying fortran code to accept this...

Cheer
David

--
David Bateman                                address@hidden
Motorola Labs - Paris                        +33 1 69 35 48 04 (Ph) 
Parc Les Algorithmes, Commune de St Aubin    +33 1 69 35 77 01 (Fax) 
91193 Gif-Sur-Yvette FRANCE

The information contained in this communication has been classified as: 

[x] General Business Information 
[ ] Motorola Internal Use Only 
[ ] Motorola Confidential Proprietary



-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
-------------------------------------------------------------