R devel - Mar 1998 - R-beta: nonlinear fitting

Thanks very much Douglas for the pointer to nlm.
Maybe the "Notes on R" maintainer can add at least a mention of nlm in
the
section on nonlinear fitting?

I never did nonlinear fitting in S-Plus before, so I have nothing to
unlearn, but I was hoping someone could show me how to do a least squares
fit with nlm.

example:
x<-c(1,2,3,4,5,6)
y<-.3*x^-.6 +.2
y<-y+rnorm(6,0,.01)

Please show me how to fit the model
y=a*x^b + c
by least squares.  I would like parameter estimates plus the standard
error for each param.

(This example could replace the current nonlinear fitting section in
"Notes on R")

Thanks very much for any help!

Bill Simpson

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[CC'ed  to R-devel, not R-help]
>>>>> "Bill" == Bill Simpson
<wsimpson@uwinnipeg.ca> writes:
    Bill> Thanks very much Douglas for the pointer to nlm.  Maybe the
    Bill> "Notes on R" maintainer can add at least a mention of nlm
in the
	   =====================    Bill> section on nonlinear fitting?

    Bill>    .....

    Bill> (This example could replace the current nonlinear fitting section
    Bill> in "Notes on R")


You are talking of  <CRAN>/doc/Rnotes.ps, or Rnotes.tgz respectively,
yes?
The first page states both R & R as authors (beside Venables & D.Smith).
However, I doubt if they consider themselves as 'maintainers' 
of these notes (due to lack of time), or do you?

	Ross?  Robert?

The problem is that these notes need more work than just ('nls'
<-> 'nlm').

Maybe I should ask again for volunteers, or maybe even a discussion 
on what could / should be done.

The notes have several sections (organized in different *.tex files) in
Rnotes.tgz.
Could(/should) we have different authors (ie. volunteers from among you)
for these sections?

About a year ago or so, Kurt Hornik proposed that these notes should become
chapter 1 -- n of ``the book'' where
the current things in  RHOME/doc/manual/Man.tex are just the appendices
(they already *are* appendices, currently).
R & R instead,  originally thought (and have also started ??) of completely
rewriting from scratch these chapters (1 -- n).

Which should be done (and by whom) ?

In the case of "R notes upgrading, 
it'd make sense if someone first works thru the current notes 
and makes them (somewhat) ``compatible'' with the  Rd.sty that we
currently use for the help-manual (i.e. the  doc/manual/... things).

------

Martin
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