> On May 24, 2017, at 1:30 PM, Ramnik Bansal <[email protected]> wrote: > > What is the cause of the error below ? > >> y <- 1 >> y[1] <- NULL > Error in y[1] <- NULL : replacement has length zero > > Thanks, > Ramnik
Hi, > length(NULL) [1] 0 You are attempting to assign NULL, which is a zero length special object of its own kind, to a specific element in the vector object 'y' and that cannot be done. You can assign NULL to 'y': y <- NULL > y NULL > length(y) [1] 0 BUT, 'y' is not a vector in that case: > is.vector(y) [1] FALSE Nor can a vector contain multiple NULLs: y <- c(NULL, NULL, NULL) > y NULL > length(y) [1] 0 Similarly: y <- c(1, NULL, 1) > y [1] 1 1 > length(y) [1] 2 Perhaps reviewing ?NULL as well as: https://cran.r-project.org/doc/manuals/r-release/R-lang.html#NULL-object might also provide some insights. Regards, Marc Schwartz ______________________________________________ [email protected] 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.
