[Rd] PR#751

Peter Dalgaard BSA p.dalgaard@biostat.ku.dk
17 Jan 2001 18:00:38 +0100


apjaworski@mmm.com writes:

> ... snip ...
> 
> > For example, in Win 98, R 1.1.1,
> >
> > > polyroot(c(2,1,1))
> >
> > correctly (per the help index) gives the roots of  1 + (1*x) + (2*x^2) as
> >
> > [1] -0.5+1.322876i -0.5-1.322876i
> 
> Mm, no. The coefficients are by increasing degree, so these are the
> roots of 2+x+x^2
> 
> ... snip ...
> 
> The manual page seems to have a typo.  It says (1.2.0 on Win)
> 
> Arguments:
> 
>        z: the vector of polynomial coefficients in decreasing order.
> 

I suppose that could be clearer (it kind of depends on what you
consider the "normal" order), but it also has

              p(x) = z1 + z2 * x + ... + z[n] * x^(n-1)

which should be clear enough.


-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk)             FAX: (+45) 35327907
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