Basically I want to create a string vector where first element is a date. >> Note that if you supply c() with objects of different types (as you have), >> the results will probably not be what you wanted.
This is the key. I assumed (not correctly) that Sys.Date() generates a character > Sys.Date() [1] "2012-01-13" but as you point out: > class(Sys.Date()) [1] "Date" and it is the best to provide c() with arguments of the same type so, in the end, explicitely casting Sys.Date() to character works for me: > N <- 2; c(as.character(Sys.Date()), sprintf('N=%d', N)) [1] "2012-01-13" "N=2" Thanks! Ryszard -------------------------------------------------------------------------- Confidentiality Notice: This message is private and may contain confidential and proprietary information. If you have received this message in error, please notify us and remove it from your system and note that you must not copy, distribute or take any action in reliance on it. Any unauthorized use or disclosure of the contents of this message is not permitted and may be unlawful. -----Original Message----- From: MacQueen, Don [mailto:macque...@llnl.gov] Sent: Thursday, January 12, 2012 5:27 PM To: Czerminski, Ryszard; r-help@r-project.org Subject: Re: [R] strange Sys.Date() side effect My best guess is that you are misunderstanding what the c() function does. I'd suggest reading the help page for c, obtained by typing ?c Note that if you supply c() with objects of different types (as you have), the results will probably not be what you wanted. Given what c() does, your output and warning message make sense. But I'm unable to figure out what you're really trying to do. Something like this, perhaps? > N <- 2; sprintf('N = %d', N) [1] "N = 2" -Don -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 On 1/10/12 5:04 AM, "Czerminski, Ryszard" <ryszard.czermin...@astrazeneca.com> wrote: >Any ideas what is the problem with this code? > >> N <- 2; c(Sys.Date(), sprintf('N = %d', N)) >[1] "2012-01-10" NA >Warning message: >In as.POSIXlt.Date(x) : NAs introduced by coercion > >Best regards, >Ryszard > >Ryszard Czerminski >AstraZeneca Pharmaceuticals LP >35 Gatehouse Drive >Waltham, MA 02451 >USA >781-839-4304 >ryszard.czermin...@astrazeneca.com > > >----------------------------------------------------------------------- --- >Confidentiality Notice: This message is private and may ...{{dropped:11}} > >______________________________________________ >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. ______________________________________________ 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.