Michael
2012-Apr-18 20:14 UTC
[R] Is there a way to find all roots of a polynomial equation in R?
Is there a way to find all roots of a polynomial equation? Lets say x^5+a*x^4+b*x^3+c*x^2+d*x+e=0 how to find its all roots? [[alternative HTML version deleted]]
Duncan Murdoch
2012-Apr-18 20:39 UTC
[R] Is there a way to find all roots of a polynomial equation in R?
On 12-04-18 4:14 PM, Michael wrote:> Is there a way to find all roots of a polynomial equation? > > Lets say > > x^5+a*x^4+b*x^3+c*x^2+d*x+e=0 > > > how to find its all roots?polyroot() should be able to do it, assuming that a,b,c,d and e are numeric or complex values, not just symbols. Duncan Murdoch
Rolf Turner
2012-Apr-18 20:49 UTC
[R] Is there a way to find all roots of a polynomial equation in R?
On 19/04/12 08:14, Michael wrote:> Is there a way to find all roots of a polynomial equation? > > Lets say > > x^5+a*x^4+b*x^3+c*x^2+d*x+e=0 > > > how to find its all roots?I believe that Galois (or maybe it was Abel) proved that this is *NOT* possible, a couple of centuries ago. However if you are thinking of *numerical* methods (i.e. supplying numerical values for a, b, ..., e before you start) then polyroot() will do it for you. As RSiteSearch("zeroes of polynomial") would have told you. (Seventh hit.) cheers, Rolf Turner
JesperHybel
2012-Apr-18 21:51 UTC
[R] Is there a way to find all roots of a polynomial equation in R?
>Is there a way to find all roots of a polynomial equation? > >Lets say > >x^5+a*x^4+b*x^3+c*x^2+d*x+e=0 > > >how to find its all roots? > >The package rootSolve might proove interesting ______________________________________________ R-help@ mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. -- View this message in context: http://r.789695.n4.nabble.com/Is-there-a-way-to-find-all-roots-of-a-polynomial-equation-in-R-tp4568892p4569100.html Sent from the R help mailing list archive at Nabble.com.