Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
1995
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 1995

[Date Index] [Thread Index] [Author Index]

Search the Archive

numerical roots of a polynomial

  • To: mathgroup at christensen.cybernetics.net
  • Subject: [mg1163] numerical roots of a polynomial
  • From: Sigurd.Schelstraete at rug.ac.be (Sigurd Schelstraete)
  • Date: Sat, 20 May 1995 02:23:23 -0400
  • Organization: University of Ghent, Belgium

hello,

does anyone know if there exists a package/function that allows one to find 
(numerically) all n roots of a polynomial of degree n, whether they are 
real or not? Since NSolve seems to be equivalent to N[Solve], it can not 
be used for generic polynomials of fifth degree or higher. Also the 
function FindRoot only allows one to find a single root near a given 
starting value (which can be complex though).

What I would like, is a function that returns the numerical values of all 
n roots as a list of substitution rules, as does Solve or NSolve. 

I guess it could be done by successively dividing out a single root found 
with FindRoot, but I'd rather first hear if anyone out there already has 
a clear-cut solution to this problem. 

All answers are appreciated.

Greetings,

Sigurd Schelstraete
University of Gent
Belgium 


  • Prev by Date: Optics
  • Next by Date: Re: BackGround Job
  • Previous by thread: Re: Optics
  • Next by thread: Re: numerical roots of a polynomial