[R] modifying colnames of tables in a loop

[Werner Wernersen]

Thanks Phil and Dimitris!

This works perfectly! 
At this stage I am not concerned about efficiency
although I am curious if there is a way to do without
copying, for instance with pointers like in C.

Thanks again,
  Werner


--- Dimitris Rizopoulos
<dimitris.rizopoulos at med.kuleuven.be> schrieb:

> try the following (untested):
> 
> tb1 <- tb2 <- tb3 <- matrix(1:100, 10, 10, dim =
> list(NULL, 
> LETTERS[1:10]))
> 
> lis <- list("tb1", "tb2", "tb3")
> for(i in seq(lis)){
>     tb <- get(lis[[i]])
>     colnames(tb) <- tolower(colnames(tb))
>     assign(lis[[i]], tb)
> }
> 
> 
> I hope it helps.
> 
> Best,
> Dimitris
> 
> ----
> Dimitris Rizopoulos
> Ph.D. Student
> Biostatistical Centre
> School of Public Health
> Catholic University of Leuven
> 
> Address: Kapucijnenvoer 35, Leuven, Belgium
> Tel: +32/(0)16/336899
> Fax: +32/(0)16/337015
> Web: http://med.kuleuven.be/biostat/
>     
>
http://www.student.kuleuven.be/~m0390867/dimitris.htm
> 
> 
> ----- Original Message ----- 
> From: "Werner Wernersen" <pensterfuzzer at yahoo.de>
> To: "Benilton Carvalho" <bcarvalh at jhsph.edu>
> Cc: <r-help at stat.math.ethz.ch>
> Sent: Thursday, November 16, 2006 4:06 PM
> Subject: Re: [R] modifying colnames of tables in a
> loop
> 
> 
> > That's almost perfect! Only the operation
> > colnames(get(x)) <-
> > seems not to be defined.
> >
> > Now I can't figure out how to assign the colnames
> of
> > the object in the original environment.
> >
> > Thanks, Benilton!
> >
> > --- Benilton Carvalho <bcarvalh at jhsph.edu>
> schrieb:
> >
> >> how about:
> >>
> >> for (x in l) colnames(get(x)) <-
> >> lower.case(colnames(get(x)))
> >>
> >> b
> >>
> >> On Nov 16, 2006, at 9:01 AM, Werner Wernersen
> wrote:
> >>
> >> > Hi,
> >> >
> >> > I have a list with the names of tables, e.g.
> >> > l <- c("t1","t2","t3")
> >> > and I want to change the colnames of each of
> the
> >> > tables in a for loop like this:
> >> > for (x in l) {
> >> >     colnames(eval(x)) <-
> >> lower.case(colnames(eval(x)))
> >> > }
> >> >
> >> > This does not work but could someone give me
> some
> >> help
> >> > to get on the right track?
> >> >
> >> > Thanks a million,
> >> >   Werner
> >> >
> >> > ______________________________________________
> >> > R-help at stat.math.ethz.ch 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 at stat.math.ethz.ch 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.
> > 
> 
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