Gavin Simpson wrote: > On Mon, 2005-09-19 at 15:34 +0200, [EMAIL PROTECTED] wrote: > >>Full_Name: Frank Wagner >>Version: R 2.1.1 >>OS: Windows >>Submission from: (NULL) (193.174.73.34) >> >> >>Hi, >>The pdf file R-intro descripe on page 27 that lists can be extended by adding >>numbers. >>Unfortunately, it's not working >>## example : >> >># if i did not declare the variable an error occurs : object not found >>mylist <- list() >>mylist[1] <- list(value1=3, value2=5) >>## Error > > > You need to use [[x]] to subset a list: > > >>mylist <- list() >>mylist[[1]] <- list(value1=3, value2=5) >>mylist > > [[1]] > [[1]]$value1 > [1] 3 > > [[1]]$value2 > [1] 5
This is a list of a list, but that is not the same as the stuff we are discussing here. See below. > >>str(mylist) > > List of 1 > $ :List of 2 > ..$ value1: num 3 > ..$ value2: num 5 > > I don't know whether there is a typo on page 27 or not: [x] is valid, it > just means something different to [[x]] - as explained on page 26 of > said manual. If it was intentional, then IMHO it is not the most clear > example of extending a list - the [[x]] notation is what I would expect > to have to use - after reading page 26 of course... Folks, please specify which version of the manual you are speaking about, e.g. by giving a chapter's/section's name. The statement on what is referred to page 27 in this thread is completly correct. Note that a list is nothing else than a vector of mode list which contains in each element a list of length one. Hence you *can* say mylist[1:2] <- list(value1=3, value2=5) or c(mylist, list(value1=3, value2=5)) or whatever. Uwe Ligges > HTH > > G ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
