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## Re: Trouble with fsolve

**From**: |
David Bateman |

**Subject**: |
Re: Trouble with fsolve |

**Date**: |
Wed, 19 Oct 2005 15:48:49 +0200 |

**User-agent**: |
Mozilla Thunderbird 0.8 (X11/20040923) |

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
`
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