Re: [R] using names with functions..
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)))
--
O__ Peter Dalgaard Øster Farimagsgade 5, Entr.B
c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K
(*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918
~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907
__
R-help@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.
Re: [R] using names with functions..
On 11/28/2007 9:52 AM, 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?
You can make just about anything into a name by quoting in in backticks,
e.g. `a.log(z)` should always be seen as a name. However, there is a
fair bit of code in contributed packages that converts things to
character vectors and then reparses it (like your example above!), and
that code may well get confused by such a name.
For example,
> deparse(quote(`a.log(z)`))
[1] "a.log(z)"
The package writer could avoid this by using
> deparse(quote(`a.log(z)`), backtick=T)
[1] "`a.log(z)`"
You also need to worry about the fact that by default, data.frame() will
convert the name of the first column to a.log.z.
So you could get everything you want with this variation on your example:
> myname<-"`a.log(z)`"
> dd<-data.frame("a.log(z)"=1:10,y=rnorm(10), check.names=FALSE)
> o<-lm(y~1,data=dd)
> fo<-as.formula(paste(".~.+",paste(myname, collapse = "+")))
> fo
. ~ . + `a.log(z)`
> update(o,formula=fo)
Call:
lm(formula = y ~ `a.log(z)`, data = dd)
Coefficients:
(Intercept) `a.log(z)`
-0.3931 0.0753
However, I'd suggest avoiding the use of such a name.
Duncan Murdoch
__
R-help@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.
Re: [R] using names with functions..
Names not conforming to the usual R syntax can be placed
in backquotes:
> `log(x)` <- 1:10
> lm(`log(x)` ~ 1)
Call:
lm(formula = `log(x)` ~ 1)
Coefficients:
(Intercept)
5.5
On Nov 28, 2007 9:52 AM, vito muggeo <[EMAIL PROTECTED]> 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
>
>
> --
>
> Vito M.R. Muggeo
> Dip.to Sc Statist e Matem `Vianelli'
> Università di Palermo
> viale delle Scienze, edificio 13
> 90128 Palermo - ITALY
> tel: 091 6626240
> fax: 091 485726/485612
>
> __
> R-help@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.
>
__
R-help@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.
[R] using names with functions..
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
--
Vito M.R. Muggeo
Dip.to Sc Statist e Matem `Vianelli'
Università di Palermo
viale delle Scienze, edificio 13
90128 Palermo - ITALY
tel: 091 6626240
fax: 091 485726/485612
__
R-help@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.
