Thank you, Peter! On Wed, Nov 16, 2016 at 4:21 PM, peter dalgaard <pda...@gmail.com> wrote: > >> On 16 Nov 2016, at 21:58 , Dimitri Liakhovitski >> <dimitri.liakhovit...@gmail.com> wrote: >> >> Hello! >> >> I need to calculate the maximum of each row of a data frame. >> This works: >> >> x <- data.frame(a = 1:5, b=11:15, c=111:115) >> x >> do.call(pmax, x) >> [1] 111 112 113 114 115 >> >> However, how should I modify it if my data frame has NAs? >> I'd like it to ignore NAs and return the maximum of all non-NAs in each row: >> >> x <- data.frame(a = c(1:5), b=11:15, c=c(111:114,NA)) >> x >> I'd like it to return: >> [1] 111 112 113 114 15 >> >> Thanks a lot! > > The first thing to notice is that pmax allows na.rm=TRUE, so it works fine to > do > >> pmax(a = c(1:5), b=11:15, c=c(111:114,NA), na.rm=TRUE) > [1] 111 112 113 114 15 > > I.e., it is your desire to use do.call() that is the challenge. The 2nd > argument should be a list containing the arguments as in the above call, so > this works too > >> do.call(pmax, list(a = c(1:5), b=11:15, c=c(111:114,NA), na.rm=TRUE)) > [1] 111 112 113 114 15 > > The form do.call(pmax,x) uses the fact that a data.frame is a kind of list. > What you need to do is to tack on the element na.rm=TRUE. This works > >> do.call(pmax, c(x, list(na.rm=TRUE))) > [1] 111 112 113 114 15 > > and it even works without the list() > >> do.call(pmax, c(x, na.rm=TRUE)) > [1] 111 112 113 114 15 > > -pd > > >> >> -- >> Dimitri Liakhovitski >> >> ______________________________________________ >> R-help@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 > Office: A 4.23 > Email: pd....@cbs.dk Priv: pda...@gmail.com > > > > > > > > >
-- Dimitri Liakhovitski ______________________________________________ R-help@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.
