Re: [R] Conditional inclusion of an element in an R object

Apologies, but all that ifelse() stuff is too hard to follow. What I would do is compute a character vector of column names to keep, then do a1[ , names.to.keep] -Don -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 On 1/10/1

Re: [R] Conditional inclusion of an element in an R object

Dear Rxperts... I would like to conditionally include an element (as a column) in a dataframe. Please see the sample code below: There is a correction to the earlier post.. my apologies... a1 <- data.frame(P=rep(1,10),Qr=LETTERS[1:10],b=letters[1:10], R=rep(c("A","B"),each=5)) lc1 <- list(C1 =

[R] Conditional inclusion of an element in an R object

Dear Rxperts... I would like to conditionally include an element (as a column) in a dataframe. Please see the sample code below: a1 <- data.frame(P=rep(1,10),Qr=LETTERS[1:10],b=letters[1:10],R=rep(c("A","B"),each=5)) lc1 <- list(C1 = "P",C2 = ifelse(is.element("Q",names(a1)),"Q",ifelse(is.elem