Well, if it is missing, how do you know what level to turn it back into?
That is what NA means in R: not available.
If you want missings to be a separate level, you could use
factor(as.character(X), exclude=NULL)
[1] A <NA> B
Levels: A B <NA>
BTW, using summary() for a length-3 object is not helpful, and please send
properly formatted text emails as the posting guide does ask of you.
On Fri, 16 Feb 2007, Jon Minton wrote:
Hi,
I expect this is simple but havent found an answer looking on the
archives...
I want to convert NA (missing) to particular levels (nonmissing) in factor
vectors.
e.g. I know
X <- c(1, 2, 3)
summary(X)
Min. 1st Qu. Median Mean 3rd Qu. Max.
1.0 1.5 2.0 2.0 2.5 3.0
X <- as.factor(X)
summary(X)
1 2 3
1 1 1
levels(X)
[1] "1" "2" "3"
levels(X) <- c("A", NA, "B")
summary(X)
A B NA's
1 1 1
But what if I want to turn the NA back into a level?
How do I do this?
Thanks, Jon
--
Brian D. Ripley, [EMAIL PROTECTED]
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
______________________________________________
[email protected] 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.
