Thanks to all for the good suggestions!!! Erin Hodgess, PhD mailto: erinm.hodg...@gmail.com
On Thu, Sep 20, 2018 at 7:38 PM Rolf Turner <r.tur...@auckland.ac.nz> wrote: > > Please see inline below. > > n 09/21/2018 01:07 PM, Peter Langfelder wrote: > > I don't know tibble, so I'll do the same with a plain data frame: > > > > a = > > > data.frame(x=LETTERS[1:4],y=1:4,z=rnorm(4),a=c("dog","cat","tree","ferret")) > >> a > > x y z a > > 1 A 1 -0.08264865 dog > > 2 B 2 0.32344426 cat > > 3 C 3 -0.80416061 tree > > 4 D 4 1.27052529 ferret > >> mean(a[2:3]) > > [1] NA > > Warning message: > > In mean.default(a[2:3]) : argument is not numeric or logical: returning > NA > >> mean(as.matrix(a[2:3])) > > [1] 1.338395 > > > > The reason you get an error on mean(a[2:3]) is that a[2:3] is still a > data > > frame (a special list) and you cannot simply apply mean to a list. You > need > > to first convert to a matrix or vector which can then be fed to mean(). > > Perhaps > > sapply(a[2:3],mean)? > > cheers, > > Rolf > > > > > Peter > > > > > > On Thu, Sep 20, 2018 at 5:50 PM Erin Hodgess <erinm.hodg...@gmail.com> > > wrote: > > > >> Hello! > >> > >> Here is a toy tibble problem: > >> > >> xt <- > >> tibble(x=LETTERS[1:4],y=1:4,z=rnorm(4),a=c("dog","cat","tree","ferret")) > >> str(xt) > >> Classes ‘tbl_df’, ‘tbl’ and 'data.frame': 4 obs. of 4 variables: > >> $ x: chr "A" "B" "C" "D" > >> $ y: int 1 2 3 4 > >> $ z: num 0.3246 0.0504 0.339 0.4872 > >> $ a: chr "dog" "cat" "tree" "ferret" > >> #No surprise > >> xt %>% mean > >> [1] NA > >> Warning message: > >> In mean.default(.) : argument is not numeric or logical: returning NA > >> #surprised! > >> mean(xt[2:3]) > >> [1] NA > >> Warning message: > >> In mean.default(xt[2:3]) : argument is not numeric or logical: > returning NA > >> xt[, 2:3] %>% mean > >> [1] NA > >> Warning message: > >> In mean.default(.) : argument is not numeric or logical: returning NA > >> > >> I have a feeling that I'm doing something silly wrong. Has anyone run > into > >> this, please? I saw something like this on this list, but didn't see a > >> solution. > >> > >> Thanks, > >> Erin > [[alternative HTML version deleted]] ______________________________________________ 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.