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RE: FW: roots of quartic equation (fwd)
- From: Matthias Winkler <Matthias dot Winkler at cern dot ch>
- To: stein at physics dot umn dot edu
- Cc: gsl-discuss at sources dot redhat dot com, <Marco dot Cattaneo at cern dot ch>
- Date: Wed, 24 Sep 2003 16:42:29 +0200 (CEST)
- Subject: RE: FW: roots of quartic equation (fwd)
Dear Andrew,
for what concerns our needs at the moment, we need it for real
coefficients only.
Cheers,
Matthias
--
---------- Forwarded message ----------
Date: Wed, 24 Sep 2003 16:34:41 +0200
From: Marco Cattaneo <Marco.Cattaneo@cern.ch>
To: Matthias Winkler <Matthias.Winkler@cern.ch>
Subject: RE: FW: roots of quartic equation (fwd)
For what it's worth, our application uses only real coefficients
> -----Original Message-----
> From: Matthias Winkler
> Sent: Wednesday, September 24, 2003 09:08
> To: Marco Cattaneo
> Subject: Re: FW: roots of quartic equation (fwd)
>
>
> Hello Marco!
>
> Fyi, I got this mail today.
>
> Cheers,
> Matthias
>
> --
>
> ---------- Forwarded message ----------
> Date: Tue, 23 Sep 2003 15:46:58 -0500 (CDT)
> From: Andrew Steiner <stein@physics.umn.edu>
> To: gsl-discuss@sources.redhat.com
> Cc: Matthias.Winkler@cern.ch
> Subject: Re: FW: roots of quartic equation (fwd)
>
> Hello all!
>
> Depending on the type of quartic you would like to solve
> (coefficients real or complex?), there are a couple options. For real
> coefficients, the C'ification of rrteq4.F would be pretty
> straightforward,
> but for complex coefficients you need something more. On the topic of
> cubics, I have found that the GSL implementation of solutions to cubic
> equations tends to be a little more accurate (for random coefficients)
> than CERNLIB.
> It is also important to know what kind of quartics you have.
> Most of these routines fail miserably for sufficiently pathological
> choices of coefficients (i.e. small odd-powered coefficients).
>
> Later,
> Andrew
>
> ----------------------------------------------------------------------
> Andrew W. Steiner Post-doctoral Research Associate
> Nuclear Theory Group University of Minnesota
> Phone: 612-624-7872 Fax: 612-624-4875
> Email: stein@physics.umn.edu URL: http://umn.edu/~stein178
> ----------------------------------------------------------------------
>
> Brian Gough writes:
> > Matthias Winkler writes:
> > > Dear GSL developers!
> > >
> > > May I forward you this question about the root of
> quartic polynomial
> > > equations in GSL. Will there be a dedicated
> gsl_poly_solve_quartic
> > > function?
> >
> > There is an empty space for it -- if someone writes a good
> > implementation it would certainly be added.
> >
> > I wasn't planning to write it myself though.
> >
> > If you specifically want the function within a fixed timescale, my
> > company can offer a GSL maintenance contract that would cover it.
> >
> > --
> > Brian
>
>
>
>