Re: [R] levels update

2008-12-05 Thread Richard . Cotton
> I hope this question is not too stupid. I would like to know how to update > levels after subsetting data from a data.frame. > > df <- data.frame(factor(c("a","a","c","b","b")), c(4,5,6,7,8), c(9,1,2,3,4)) > names(df) <- c("X1","X2","X3") > > my.sub <- subset(df, X1 == "a" | X1 == "b") > lev

Re: [R] levels update

2008-12-05 Thread Antje
Thanks a lot!!! the "drop" thing was exactly what I was looking for (I already used it some time ago but forgot about it). Thanks to everybody else too. Antje Prof Brian Ripley schrieb: On Fri, 5 Dec 2008, jim holtman wrote: try this: df <- data.frame(factor(c("a","a","c","b","b")), c(4,

Re: [R] levels update

2008-12-05 Thread Prof Brian Ripley
On Fri, 5 Dec 2008, jim holtman wrote: try this: df <- data.frame(factor(c("a","a","c","b","b")), c(4,5,6,7,8), c(9,1,2,3,4)) names(df) <- c("X1","X2","X3") my.sub <- subset(df, X1 == "a" | X1 == "b") levels(my.sub$X1) [1] "a" "b" "c" my.sub$X1 <- factor(my.sub$X1) I find my.sub$X1 <- my

Re: [R] levels update

2008-12-05 Thread hadley wickham
On Fri, Dec 5, 2008 at 6:50 AM, Antje <[EMAIL PROTECTED]> wrote: > Hello, > > I hope this question is not too stupid. I would like to know how to update > levels after subsetting data from a data.frame. > > df <- data.frame(factor(c("a","a","c","b","b")), c(4,5,6,7,8), c(9,1,2,3,4)) > names(df) <-

Re: [R] levels update

2008-12-05 Thread Erich Neuwirth
I do the following for a subsetted dataframe: cleanfactors <- function(mydf){ outdf<-mydf for (i in 1:dim(mydf)[2]){ if (is.factor(mydf[,i])) outdf[,i]<-factor(mydf[,i]) } outdf } Antje wrote: > Hello, > > I hope this question is not too stupid. I would like to know how to > update

Re: [R] levels update

2008-12-05 Thread jim holtman
try this: > df <- data.frame(factor(c("a","a","c","b","b")), c(4,5,6,7,8), c(9,1,2,3,4)) > names(df) <- c("X1","X2","X3") > > my.sub <- subset(df, X1 == "a" | X1 == "b") > levels(my.sub$X1) [1] "a" "b" "c" > my.sub$X1 <- factor(my.sub$X1) > levels(my.sub$X1) [1] "a" "b" > On Fri, Dec 5, 2008 at

[R] levels update

2008-12-05 Thread Antje
Hello, I hope this question is not too stupid. I would like to know how to update levels after subsetting data from a data.frame. df <- data.frame(factor(c("a","a","c","b","b")), c(4,5,6,7,8), c(9,1,2,3,4)) names(df) <- c("X1","X2","X3") my.sub <- subset(df, X1 == "a" | X1 == "b") levels(my.s