[R] using names with functions..

[Peter Dalgaard]

vito muggeo wrote:
> Dear all,
> I have the following (rather) strange problem..
> For some reasons, I finally work with a variable whose name includes an 
> R function, "a.log(z)", say. And that is a problem when I call it in a 
> formula, for instance:
>
>  > myname<-"a.log(z)"
>  > dd<-data.frame("a.log(z)"=1:10,y=rnorm(10))
>  > o<-lm(y~1,data=dd)
>  > fo<-as.formula(paste(".~.+",paste(myname, collapse = "+")))
>  > fo
> . ~ . + a.log(z)
>  > update(o,formula=fo)
> Error in eval(expr, envir, enclos) : could not find function "a.log"
>  >
>
> How can fit the model? namely how can I use "a.log(z)" in the example above?
>
> Many thanks,
> vito
>
>
>   
Use backquotes as in `a.log(z)`, I think.

myname<-"a.log(z)"
o<-lm(y~1,data=dd)
dd<-data.frame("a.log(z)"=1:10,y=rnorm(10),check.names=F)
fo<-as.formula(paste(".~.+",paste(deparse(as.name(myname), backtick=T),
collapse = "+")))
update(o,formula=fo)

or, actually nicer, use

fo <- bquote(. ~ . + .(as.name(myname)))


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