From octave-sources-request at bevo dot che dot wisc dot edu  Wed Jul 26 21:07:39 2000
Subject: Re: invroots : inversion of polynomial 'roots'-function (incl demo)
From: pkienzle at kienzle dot powernet dot co dot uk (Paul Kienzle)
To: fabian at tu-cottbus dot de, octave-sources@bevo.che.wisc.edu
Date: Thu, 27 Jul 2000 03:16:04 +0100 (BST)

From: Rolf Fabian <fabian at tu-cottbus dot de>
>Hi,
>
>the attached ,invroots' function  is something missing in octave's polynomial toolbox !
>
>	P = invroots ( x0 )
>
>it inverts the available ,roots' function in the following sense, that it
>returns the normalized polynomial P of degree N
>( i.e. highest exponents coefficient  set to 1), 
>which	PASSES though ALL ROOTS
>given by the N elements of input vector  x0

poly(x0) does what you want.

Paul Kienzle
pkienzle at kienzle dot powernet dot co dot uk



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

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