On Tue, 26 Feb 2019, Brian Montgomery via R-devel wrote: > The following code crashes after about 300 iterations on my > x86_64-w64-mingw32 machine on R 3.5.2 --vanilla. > Others have duplicated this (see > https://github.com/tidyverse/magrittr/issues/190 if necessary), but I don't > know how machine/OS-dependent it may be. > If it doesn't crash for you, please try increasing the length of the x vector. > > Substituting the commented-out line for the one below it works correctly > (prints out 1:1000 and ends normally) every time. > > x <- 1:200000 > y <- rep(letters[1:5], length(x) / 5L) > for (i in 1:1000) { > # x[y == 'a'] <- x[y == 'b'] > x <- `[<-`(x, y == 'a', x[y == 'b']) > cat(i, '') > } > cat('\n') > > The point of using this syntax is to make it work better with pipes, but the > errors occur without pipes or magrittr.
Calling replacement functions this way is a Really Bad Idea. Some assume they are being called properly and will end up mutating data they should not when called this way. Best, luke > > Thank you for your help! > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > -- Luke Tierney Ralph E. Wareham Professor of Mathematical Sciences University of Iowa Phone: 319-335-3386 Department of Statistics and Fax: 319-335-3017 Actuarial Science 241 Schaeffer Hall email: luke-tier...@uiowa.edu Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
