Dear All, I just want to remove “NA” from the levels of a factor. For example:
d<-data.frame(matrix(c("ww","ww","xx","yy","ww","yy","xx","yy","NA"), ncol=3, byrow=TRUE)) > factor(d[, 3], exclude=NA) [1] xx yy NA Levels: NA xx yy But “NA” is still listed in the levels. How can I solve this problem? Thanks in advance. Lisa -- View this message in context: http://r.789695.n4.nabble.com/Factor-function-tp3473984p3473984.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.