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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
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David Bateman address@hidden
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