Heinz, Try this:
lapply(DF, function(x)names(DF)[as.numeric(gsub("[^0-9]", "", deparse(substitute(x))))]) On Mon, Sep 28, 2009 at 8:43 AM, Heinz Tuechler <tuech...@gmx.at> wrote: > Thank you, Henrique, > > my example was simplified. In a more complexe function I want to use the > objects, not just their names. In your solution, I have to adapt the > function itself, depending on the name of the data.frame, which I would like > to avoid. > > Thanks, > Heinz > > > At 13:36 28.09.2009, Henrique Dallazuanna wrote: >> >> You can use names insteed: >> >> DF <- data.frame(a=1:3, b=2:4) >> lapply(names(DF), function(x){ >> print(x) >> DF[x] >> }) >> >> On Mon, Sep 28, 2009 at 8:22 AM, Heinz Tuechler <tuech...@gmx.at> wrote: >> > Dear All, >> > >> > to produce output of several columns of a data frame, I tried to use >> > lapply >> > and also l_ply. In both cases, I would like to print a header line >> > containing also the name of the respective column in the data frame. >> > >> > For example, I would like the following >> > >> > lapply(data.frame(a=1:3, b=2:4), function(x) >> > print(deparse(substitute(x)))) >> > >> > to produce: >> > [1] "a" >> > [1] "b" >> > >> > and not, what it actually does: >> > [1] "X[[1L]]" >> > [1] "X[[2L]]" >> > $a >> > [1] "X[[1L]]" >> > >> > $b >> > [1] "X[[2L]]" >> > >> > or with l_ply (plyr package) >> > l_ply(data.frame(a=1:3, b=2:4), function(x) >> > print(deparse(substitute(x)))) >> > >> > to produce: >> > [1] "a" >> > [1] "b" >> > >> > and not, what it actually does: >> > [1] ".data[[i]]" >> > [1] ".data[[i]]" >> > >> > Is this possible? >> > >> > Thanks, >> > Heinz >> > >> > ______________________________________________ >> > 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. >> > >> >> >> >> -- >> Henrique Dallazuanna >> Curitiba-Paraná-Brasil >> 25° 25' 40" S 49° 16' 22" O > > > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O ______________________________________________ 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.