For example: a <- 1
f <- function(b){ return(a+b) } when we call function f(2), r will search the local environment first, if it cannot find a, it will search global environment, and return 3. How to avoid r searching the global environment and return an error when we call this function? Thanks. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list 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.