You can use structure() to attach the names to a list that is input to
data.frame.
E.g.,
dfNames <- c("First", "Second Name")
data.frame(lapply(structure(dfNames, names=dfNames),
function(name)rep(NA_real_, 5)))
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Tue, Mar 31, 2015 at 11:37 AM, Sarah Goslee <sarah.goslee at gmail.com>
wrote:
> Hi,
>
> Duncan Murdoch suggested:
>
> > The matrix() function has a dimnames argument, so you could do this:
> >
> > names <- c("strat", "id", "pid")
> > data.frame(matrix(NA, nrow=10, ncol=3, dimnames=list(NULL, names)))
>
> That's a definite improvement, thanks. But no way to skip matrix()? It
> just seems unRlike, although since it's only full of NA values there
> are no coercion issues with column types or anything, so it doesn't
> hurt. It's just inelegant. :)
>
> Sarah
> --
> Sarah Goslee
> http://www.functionaldiversity.org
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>
[[alternative HTML version deleted]]
If you don't mind an extra column, you could use something similar to:
data.frame(r=seq(8),foo=NA,bar=NA)
If you do, here is another approach (see function body):
empty.frame <- function (r = 1, n = 1, fill = NA_real_) {
data.frame(setNames(lapply(rep(fill, length(n)), rep, times=r), n))
}
empty.frame()
empty.frame(, seq(3))
empty.frame(8, c("foo", "bar"))
I could not put it in one line either, without retyping at least one
argument (n in this case).
So I suggest a function is the way to go for a simplified syntax ...
Thanks to all for the ideas!
Sven
On 31 March 2015 at 20:55, William Dunlap <wdunlap at tibco.com> wrote:
> You can use structure() to attach the names to a list that is input to
> data.frame.
> E.g.,
>
> dfNames <- c("First", "Second Name")
> data.frame(lapply(structure(dfNames, names=dfNames),
> function(name)rep(NA_real_, 5)))
>
>
> Bill Dunlap
> TIBCO Software
> wdunlap tibco.com
>
> On Tue, Mar 31, 2015 at 11:37 AM, Sarah Goslee <sarah.goslee at
gmail.com>
> wrote:
>
> > Hi,
> >
> > Duncan Murdoch suggested:
> >
> > > The matrix() function has a dimnames argument, so you could do
this:
> > >
> > > names <- c("strat", "id", "pid")
> > > data.frame(matrix(NA, nrow=10, ncol=3, dimnames=list(NULL,
names)))
> >
> > That's a definite improvement, thanks. But no way to skip
matrix()? It
> > just seems unRlike, although since it's only full of NA values
there
> > are no coercion issues with column types or anything, so it
doesn't
> > hurt. It's just inelegant. :)
> >
> > Sarah
> > --
> > Sarah Goslee
> > http://www.functionaldiversity.org
> >
> > ______________________________________________
> > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > 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.
> >
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>
[[alternative HTML version deleted]]
I got rid of the extra column. data.frame(r=seq(8), foo=NA, bar=NA, row.names="r") Rich On Tue, Mar 31, 2015 at 6:18 PM, Sven E. Templer <sven.templer at gmail.com> wrote:> If you don't mind an extra column, you could use something similar to: > > data.frame(r=seq(8),foo=NA,bar=NA) > > If you do, here is another approach (see function body): > > empty.frame <- function (r = 1, n = 1, fill = NA_real_) { > data.frame(setNames(lapply(rep(fill, length(n)), rep, times=r), n)) > } > empty.frame() > empty.frame(, seq(3)) > empty.frame(8, c("foo", "bar")) > > I could not put it in one line either, without retyping at least one > argument (n in this case). > So I suggest a function is the way to go for a simplified syntax ... > > Thanks to all for the ideas! > Sven > > On 31 March 2015 at 20:55, William Dunlap <wdunlap at tibco.com> wrote: > >> You can use structure() to attach the names to a list that is input to >> data.frame. >> E.g., >> >> dfNames <- c("First", "Second Name") >> data.frame(lapply(structure(dfNames, names=dfNames), >> function(name)rep(NA_real_, 5))) >> >> >> Bill Dunlap >> TIBCO Software >> wdunlap tibco.com >> >> On Tue, Mar 31, 2015 at 11:37 AM, Sarah Goslee <sarah.goslee at gmail.com> >> wrote: >> >> > Hi, >> > >> > Duncan Murdoch suggested: >> > >> > > The matrix() function has a dimnames argument, so you could do this: >> > > >> > > names <- c("strat", "id", "pid") >> > > data.frame(matrix(NA, nrow=10, ncol=3, dimnames=list(NULL, names))) >> > >> > That's a definite improvement, thanks. But no way to skip matrix()? It >> > just seems unRlike, although since it's only full of NA values there >> > are no coercion issues with column types or anything, so it doesn't >> > hurt. It's just inelegant. :) >> > >> > Sarah >> > -- >> > Sarah Goslee >> > http://www.functionaldiversity.org >> > >> > ______________________________________________ >> > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >> > 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. >> > >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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. >> > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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.
> On 31 Mar 2015, at 20:55 , William Dunlap <wdunlap at tibco.com> wrote: > > You can use structure() to attach the names to a list that is input to > data.frame. > E.g., > > dfNames <- c("First", "Second Name") > data.frame(lapply(structure(dfNames, names=dfNames), > function(name)rep(NA_real_, 5))) >Yes, I cooked up something similar: names <- c("foo","bar","baz") names(names) <- names # confuse 'em.... as.data.frame(lapply(names, function(x) rep(NA_real_,10))) but wouldn't it be more to the point to do df <- as.data.frame(rep(list(rep(NA_real_, 10)),3)) names(df) <- names ? The lapply() approach could be generalized to a vector of column classes, though. A general solution looks impracticable; once you start considering how to specify factor columns with each their own level set, things get a bit out of hand. -pd> > Bill Dunlap > TIBCO Software > wdunlap tibco.com > > On Tue, Mar 31, 2015 at 11:37 AM, Sarah Goslee <sarah.goslee at gmail.com> > wrote: > >> Hi, >> >> Duncan Murdoch suggested: >> >>> The matrix() function has a dimnames argument, so you could do this: >>> >>> names <- c("strat", "id", "pid") >>> data.frame(matrix(NA, nrow=10, ncol=3, dimnames=list(NULL, names))) >> >> That's a definite improvement, thanks. But no way to skip matrix()? It >> just seems unRlike, although since it's only full of NA values there >> are no coercion issues with column types or anything, so it doesn't >> hurt. It's just inelegant. :) >> >> Sarah >> -- >> Sarah Goslee >> http://www.functionaldiversity.org >> >> ______________________________________________ >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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. >> > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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.-- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd.mes at cbs.dk Priv: PDalgd at gmail.com
> but wouldn't it be more to the point to do > > df <- as.data.frame(rep(list(rep(NA_real_, 10)),3)) > names(df) <- namesAs a matter of personal style (and functional programming sensibility), I prefer not to make named objects and then modify them. Also, the names coming out of that as.data.frame call are exceedingly ugly and I'd rather not generate them at all. Also adding the names after calling data.frame means can give different results than passing them into data.frame(), which can mangle nonsyntactic names like "Second Name" into "Second.Name". It is often preferable, but it is different. Bill Dunlap TIBCO Software wdunlap tibco.com On Fri, Apr 3, 2015 at 5:51 AM, peter dalgaard <pdalgd at gmail.com> wrote:> > > On 31 Mar 2015, at 20:55 , William Dunlap <wdunlap at tibco.com> wrote: > > > > You can use structure() to attach the names to a list that is input to > > data.frame. > > E.g., > > > > dfNames <- c("First", "Second Name") > > data.frame(lapply(structure(dfNames, names=dfNames), > > function(name)rep(NA_real_, 5))) > > > > Yes, I cooked up something similar: > > names <- c("foo","bar","baz") > names(names) <- names # confuse 'em.... > as.data.frame(lapply(names, function(x) rep(NA_real_,10))) > > but wouldn't it be more to the point to do > > df <- as.data.frame(rep(list(rep(NA_real_, 10)),3)) > names(df) <- names > > ? > > The lapply() approach could be generalized to a vector of column classes, > though. > > A general solution looks impracticable; once you start considering how to > specify factor columns with each their own level set, things get a bit out > of hand. > > -pd > > > > > Bill Dunlap > > TIBCO Software > > wdunlap tibco.com > > > > On Tue, Mar 31, 2015 at 11:37 AM, Sarah Goslee <sarah.goslee at gmail.com> > > wrote: > > > >> Hi, > >> > >> Duncan Murdoch suggested: > >> > >>> The matrix() function has a dimnames argument, so you could do this: > >>> > >>> names <- c("strat", "id", "pid") > >>> data.frame(matrix(NA, nrow=10, ncol=3, dimnames=list(NULL, names))) > >> > >> That's a definite improvement, thanks. But no way to skip matrix()? It > >> just seems unRlike, although since it's only full of NA values there > >> are no coercion issues with column types or anything, so it doesn't > >> hurt. It's just inelegant. :) > >> > >> Sarah > >> -- > >> Sarah Goslee > >> http://www.functionaldiversity.org > >> > >> ______________________________________________ > >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > >> 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. > >> > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > > 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. > > -- > Peter Dalgaard, Professor, > Center for Statistics, Copenhagen Business School > Solbjerg Plads 3, 2000 Frederiksberg, Denmark > Phone: (+45)38153501 > Email: pd.mes at cbs.dk Priv: PDalgd at gmail.com > > > > > > > > >[[alternative HTML version deleted]]