Thanks for the correction, I learned something new. Peter
On Fri, Aug 21, 2015 at 7:32 AM, Bert Gunter <bgunter.4...@gmail.com> wrote: > Inline. > > -- Bert > Bert Gunter > > "Data is not information. Information is not knowledge. And knowledge > is certainly not wisdom." > -- Clifford Stoll > > > On Thu, Aug 20, 2015 at 10:47 PM, Peter Langfelder > <peter.langfel...@gmail.com> wrote: >> On Thu, Aug 20, 2015 at 10:04 PM, Bert Gunter <bgunter.4...@gmail.com> wrote: >> >>>> I noticed you made two data-frames, ‘my4s' and ‘my4S'. The `my4S` was >>>> built with `cbind` which would create a matrix (probably a character >>>> matrix) rather than a data frame. >>> >>> False. There is a data.frame method for cbind that returns a data >>> frame. Don't know the specifics here, though. >>> >> >> True, but does not apply here, i.e., David is correct. cbind will >> return a data frame if the first argument is a data frame. In the OP >> case, the first argument was a vector and hence cbind gives a matrix, > > False again. > > class(cbind(a=1:5,b=data.frame(a=letters[1:5],b=3:7))) > > [1] "data.frame" > > ##First argument a vector, but data frame is returned. Please consult > ?cbind -- especially the data frame section -- for details. > > Again, I don't know the specifics here, and you and David may still > well be right for what the OP did. I am only trying to correct what > appear to me to be incorrect statements about the data.frame method of > cbind (or rbind). Apologies if I have misinterpreted. > > Cheers, > Bert > > > >> of mode "character" if any of the inputs were character. Here's a >> short demo: >> >>> a = data.frame(a1 = 1:10) >> # First argument a data frame, so the results is also a data frame : >>> class(cbind(a, b = 11:20)) >> [1] "data.frame" >> # First argument is a vector, so the result is a matrix: >>> class(cbind(a$a1, b = 11:20)) >> [1] "matrix" >>> mode(cbind(a$a1, b = 11:20)) >> [1] "numeric" >>> mode(cbind(a$a1, b = letters[11:20])) >> [1] "character" >> >> Peter ______________________________________________ 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.
