[Rd] Buglet/omission in nls package (PR#6901)
Prof Brian Ripley
ripley at stats.ox.ac.uk
Sat May 22 12:42:31 CEST 2004
Berwin,
No one has said the coef() will work on a summary object, but it would be
nice if it did where appropriate.
I've added an summary.nls method for 2.0.0.
Brian
On Fri, 21 May 2004 berwin at maths.uwa.edu.au wrote:
> Dear all,
>
> I noticed the following under R 1.8.1 (when nls was still a separate
> package) but the same problem occurs under R 1.9.0 (where most (all?)
> of nls is now in the stats package):
`all of nls', indeed.
> > data(Puromycin)
> > fm <- nls(rate~SSmicmen(conc,b0,b1), Puromycin, subset = state=="treated")
> > coef(summary(fm))
> NULL
>
> The problem seems to be that summary.nls uses the name "parameters"
> instead of the name "coefficients" for the matrix with the estimates,
> standard errors, t values and p values:
>
> > summary(fm)$parameters
> Estimate Std. Error t value Pr(>|t|)
> b0 212.68370728 6.947153198 30.614512 3.241160e-11
> b1 0.06412123 0.008280944 7.743227 1.565136e-05
>
> Thus, coef.default fails on an object of class "summary.nls".
>
> Possible fixes:
> 1) Rename that part of the summary.nls structure from parameters to
> coefficients (not sure if that breaks something else); or
> 2) Write a coef.summary.nls method that returns the structure
> parameter from a summary.nls object passed to it.
>
> Cheers,
>
> Berwin
>
> --please do not edit the information below--
>
> Version:
> platform = i686-pc-linux-gnu
> arch = i686
> os = linux-gnu
> system = i686, linux-gnu
> status =
> major = 1
> minor = 9.0
> year = 2004
> month = 04
> day = 12
> language = R
>
> Search Path:
> .GlobalEnv, package:methods, package:stats, package:graphics, package:utils, Autoloads, package:base
>
> ______________________________________________
> R-devel at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-devel
>
>
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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