R help - Aug 2012 - define subset argument for function lm as variable?

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

Hi Rainer,

You could try:

subs <- expression(dead==FALSE & recTreat==FALSE)

lme(formula, subset = eval(subs))

Not tested, but something along those lines should work.

Cheers,

Josh

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
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.


-- 
Joshua Wiley
Ph.D. Student, Health Psychology
Programmer Analyst II, Statistical Consulting Group
University of California, Los Angeles
https://joshuawiley.com/

?? 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
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.


-- 

Bert Gunter
Genentech Nonclinical Biostatistics

Internal Contact Info:
Phone: 467-7374
Website:
http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm