Years ago, I did lots of Perl programming. Perl will let you be lazy and write functions that refer to undefined variables (like R does), but there is also a strict mode so the interpreter will block anything when a variable is mentioned that has not been defined. I wish there were a strict mode for checking R functions.
Here's why. We have a lot of students writing R functions around here and they run into trouble because they use the same name for things inside and outside of functions. When they call functions that have mistaken or undefined references to names that they use elsewhere, then variables that are in the environment are accidentally used. Know what I mean? dat <- whatever someNewFunction <- function(z, w){ #do something with z and w and create a new "dat" # but forget to name it "dat" lm (y, x, data=dat) # lm just used wrong data } I wish R had a strict mode to return an error in that case. Users don't realize they are getting nonsense because R finds things to fill in for their mistakes. Is this possible? Does anybody agree it would be good? -- Paul E. Johnson Professor, Political Science 1541 Lilac Lane, Room 504 University of Kansas ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel