Hi folks,
Could you please help me to understand; An Introduction to R http://cran.r-project.org/doc/manuals/R-intro.html#Logical-vectors The function is.na(x) gives a logical vector of the same size as x with value TRUE if and only if the corresponding element in x is NA. > z <- c(1:3,NA); ind <- is.na(z) and Note that there is a second kind of “missing” values which are produced by numerical computation, the so-called Not a Number, NaN, values. Examples are > 0/0 or > Inf - Inf the explanation being abstract to me to understand. TIA 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.
