[R] gnls warning message

[Prof Brian Ripley]

>From the help page:

  control: a list of control values ...

Now, control=c(minFactor=1/2048) is not a list but a numeric vector.
So it is warning you about incorrect usage.

On Thu, 26 Apr 2007, Pedro Mardones wrote:

> Dear R users;
> I was trying to fit a nonlinear model using gnls (nlme version 3.1-80,
> R 2.5.0, WinXP) and I got the following error and warning message:
>
> Error in gnls(ht ~ a1 * hd * (1 - a2 * exp(-a3 * (dbh/dq2))), data = hdat,  :
>        Step halving factor reduced below minimum in NLS step
> In addition: Warning message:
> $ operator is deprecated for atomic vectors, returning NULL in:
> control$nlmStepMax
>
> What is new for me is the warning message. It appears when I try to
> specify different settings using the control statement.For example:
>
>> hm02<-gnls(ht~a1*hd*(1-a2*exp(-a3*(dbh/dq2))),data=hdat,
> + start=c(a1=1.04,a2=1.38,a3=2.88),weights=varExp(),
> + control=c(minFactor=1/2048))
>
> Any comment will be appreciate
>
> Thanks
> PM
>
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> and provide commented, minimal, self-contained, reproducible code.
>

-- 
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)
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