Greetings. I somehow had the impression that an infinite number, as obtained by dividing by zero, for instance, would be flagged as both missing ("NA") and not a number ("NaN"). It appears that I was wrong on both counts, although the is.finite function correctly returns FALSE in such a case. Please see the appended for some details. I guess that the bottom line is that R works the way it works, but if you can add anything that will further instruct me, I'd appreciate it.
Thanks. -- Mike > y <- 2/0 > y [1] Inf > is.na(y) [1] FALSE > is.nan(y) [1] FALSE > is.finite(y) [1] FALSE > z <- log(-1) Warning message: In log(-1) : NaNs produced > z [1] NaN > is.nan(z) [1] TRUE > is.na(z) [1] TRUE ----- R version 2.9.2 (2009-08-24) Copyright (C) 2009 The R Foundation for Statistical Computing ISBN 3-900051-07-0 ----- $ uname -a Linux xxxxxxx.localdomain 2.6.29.6-217.2.16.fc11.x86_64 #1 SMP Mon Aug 24 17:17:40 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux ______________________________________________ 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.