http://www.netlib.org/
Mike
Daniel Kidger wrote:
> Alexsander,
> However the solution for a cubic is not difficult - Cardano's formula is
> standard explicit method.
> I implemented some years ago - although I cant find my source at the moment.
> :-(
>
> I suggest you do a web search for "Cubic" and "Cardano" (and "Fortran").
>
> Several standard maths libraries have it, such as c02alc in the NAg
> libraries and also Numerical Recipes, but I guess you want open source.
>
> Hopefully someone else can post some source code?
>
> Yours,
> Daniel.
>
> --------------------------------------------------------------
> Dr. Dan Kidger, Quadrics Ltd. [log in to unmask]
> One Bridewell St., Bristol, BS1 2AA, UK 0117 915 5505
> ----------------------- www.quadrics.com --------------------
>
> -----Original Message-----
> From: Aleksandar N. Donev [mailto:[log in to unmask]]
> Sent: 17 February 2003 15:15
> To: [log in to unmask]
> Subject: Quartic equations
>
> Hello,
>
> Does someone have a routine for a quartic polynomial root solver? I need
> to find the smalles real positive root of a quartic polynomial or know
> that it does not exist. In cases when it does exist, it is likely that I
> have a very good initial guess just by solving the corresponding quadratic
> equation (ignoring two terms, since they are small!), but simply deciding
> whether there is a positive real root seems hard (Sturm sequences?). The
> code will be used in public-domain libraries.
>
> Any advice from the experiences appreciated.
> Snowed-In Aleksandar
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