Simply put, I want to subset the data frame 'a' where 'y=0'. > a <- as.data.frame(cbind(x=1:10, y=c(1,0,NA,1,0,NA,NA,1,1,0))) > a x y 1 1 1 2 2 0 3 3 NA 4 4 1 5 5 0 6 6 NA 7 7 NA 8 8 1 9 9 1 10 10 0
> names(a) [1] "x" "y" > table(a$y) 0 1 3 4 > table(a$y, useNA="always") 0 1 <NA> 3 4 3 > b <- a[a$y==0,] > b x y 2 2 0 NA NA NA 5 5 0 NA.1 NA NA NA.2 NA NA 10 10 0 > is(a$y) [1] "numeric" "vector" Instead of only pulling the rows where a$y==0, i'm getting where they're 0, OR NA. ? Again I feel like either something was changed when I wasn't looking.. or I'm reaaaaaaly forgetting something important. Thanks, Robin Jeffries MS, DrPH Candidate Department of Biostatistics, UCLA 530-633-STAT(7828) rjeffr...@ucla.edu [[alternative HTML version deleted]] ______________________________________________ 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.