Below. -- Bert On Fri, Jul 15, 2011 at 10:31 AM, andrewH <ahoer...@rprogress.org> wrote: > Thanks, everybody, this has been very edifying. One last question: > > It seems that sometimes when a function returns something and you don't > assign it, it prints to the console, and sometimes it doesn't. I'm not sure > I understand which is which. My best current theory is that, if the function > returns NULL, by itself and not as part of some larger object, it does not > print it, but non-null values are printed. Is that correct?
-- No. It depends on whether the function uses invisible() in the return, ?invisible If invisible() is not used and the value is not assigned, it's printed. Otherwise not.cf: f <- function()NULL g <- function()invisible(NULL) f() ## NULL is printed g() ## nothing printed z1 <- f() ## nothing printed z2 <- g() ## nothing printed z1 ## NULL z2 ##NULL Cheers, Bert > > Thanks! Andrew > > > -- > View this message in context: > http://r.789695.n4.nabble.com/Using-str-in-a-function-tp3655785p3670513.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. > -- "Men by nature long to get on to the ultimate truths, and will often be impatient with elementary studies or fight shy of them. If it were possible to reach the ultimate truths without the elementary studies usually prefixed to them, these would not be preparatory studies but superfluous diversions." -- Maimonides (1135-1204) Bert Gunter Genentech Nonclinical Biostatistics ______________________________________________ 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.
