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

[Rainer M Krug]

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

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