[R] Is there a way to find all roots of a polynomial equation in R?

Jeff Newmiller jdnewmil at dcn.davis.CA.us
Thu Apr 19 04:49:07 CEST 2012


not much to speak of.
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Sent from my phone. Please excuse my brevity.

Michael <comtech.usa at gmail.com> wrote:

>how much accuracy does it have when I have a polynomial of thousands of
>orders?
>
>Thank you!
>
>On Wed, Apr 18, 2012 at 3:49 PM, Rolf Turner <rolf.turner at xtra.co.nz>
>wrote:
>
>>  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
>>
>
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>
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