----- Original Message ---- From: Robert Baer <rb...@atsu.edu> To: Stephen Liu <sati...@yahoo.com>; r-help@r-project.org Sent: Wed, August 18, 2010 2:43:27 AM Subject: Re: [R] Missing values
Hi Robert, - snip - >> z <- c(1:3,NA); ind <- is.na(z) ># To see the logical vector the same size as the original print them out ># z has four elements, one of which is "not available" or "not applicable" >z > [1] 1 2 3 NA > ># ind has four LOGICAL elements, the last of which is "not available" ># so the function is.na() returns TRUE >ind # logical elements >[1] FALSE FALSE FALSE TRUE Now I understand. Thanks - snip - >>NaN means that the value wasn't missing but can't be expressed as a >>number. 0/0 is NaN because the result is mathematically undefined > # Are you reading zero divided by zero in the line above? I read it as "OR". It should be "division/divide" ? >> Inf - Inf > # infinity and minus infinity I see. It is "minus" sign NOT "to" B.R. Stephen L ______________________________________________ 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.
