[R] define subset argument for function lm as variable?

[Bert Gunter]

?? I do not groc what you mean. ... subset == subs would work fine in
your lm call. So unless someone else does get it, you may need to
elaborate.

In general, ?substitute, ?bquote, and ?quote are useful to avoid
immediate evaluation of calls, but I don't know if that's relevant to
what you want here.

-- Bert

On Tue, Aug 21, 2012 at 7:44 AM, Rainer M Krug <r.m.krug at gmail.com> wrote:
> Hi
>
> I want to do a series of linear models, and would like to define the input
> arguments for lm() as variables. I managed easily to define the formula
> arguments in a variable, but I also would like to have the "subset" in a
> variable. My reasoning is, that I have the subset in the results object.
>
> So I wiould like to add a line like:
>
> subs <- dead==FALSE & recTreat==FALSE
>
> which obviously does not work as the expression is evaluated immediately. Is
> is it possible to do what I want to do here, or do I have to go back to use
>
> dat <- subset(dat, dead==FALSE & recTreat==FALSE)
>
> ?
>
>
>
> dat <- loadSPECIES(SPECIES)
> feff <- height~pHarv*year               # fixed effect in the model
> reff <- ~year|plant                     # random effect in the model, where
> year is the
> dat.lme <- lme(
>              fixed = feff,                           # fixed effect in the
> model
>              data  = dat,
>              random = reff,                          # random effect in the
> model
>              correlation = corAR1(form=~year|plant), #
>              subset = dead==FALSE & recTreat==FALSE, #
>              na.action = na.omit
>              )
> dat.lm <- lm(
>             formula =  feff,              # fixed effect in the model
>             data = dat,
>             subset = dead==FALSE & recTreat==FALSE,
>             na.action = na.omit
>             )
>
> Thanks,
>
> Rainer
>
> --
> Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation Biology,
> UCT), Dipl. Phys. (Germany)
>
> Centre of Excellence for Invasion Biology
> Stellenbosch University
> South Africa
>
> Tel :       +33 - (0)9 53 10 27 44
> Cell:       +33 - (0)6 85 62 59 98
> Fax :       +33 - (0)9 58 10 27 44
>
> Fax (D):    +49 - (0)3 21 21 25 22 44
>
> email:      Rainer at krugs.de
>
> Skype:      RMkrug
>
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-- 

Bert Gunter
Genentech Nonclinical Biostatistics

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