Recoding multiple TRUE/FALSE columns into a single list of TRUE columns
Try this:
x <- read.table(text = " P1 P2 P3 P4
+ 1 0 0 1 1 + 2 0 1 1 1 + 3 1 0 0 0 + 4 0 0 0 0 + 5 1 1 1 1 ", header = TRUE)
labs <- apply(x, 1, function(.row){
+ indx <- which(.row == 1) + if (length(indx) > 0) return(paste(names(x)[indx], collapse = ',')) + else return(NA) + })
x$result <- labs x
P1 P2 P3 P4 result 1 0 0 1 1 P3,P4 2 0 1 1 1 P2,P3,P4 3 1 0 0 0 P1 4 0 0 0 0 <NA> 5 1 1 1 1 P1,P2,P3,P4
On Sun, Dec 25, 2011 at 7:30 PM, David Epstein <davideps at umich.edu> wrote:
Hi everyone, I need to recode multiple columns in a dataframe into a single column in a variety of different ways. ?Often the values will be TRUE/FALSE and I want a list of the columns that are true as in the Result column below: ? ?P1 ? P2 ? P3 ? P4 ? Result 1 ? 0 ? ?0 ? ?1 ? ?1 ? ?P3,P4 2 ? 0 ? ?1 ? ?1 ? ?1 ? ?P2,P3,P4 3 ? 1 ? ?0 ? ?0 ? ?0 ? ?P1 4 ? 0 ? ?0 ? ?0 ? ?0 ? ?NA 5 ? 1 ? ?1 ? ?1 ? ?1 ? ?P1,P2,P3,P4 I'm still relatively new to R and tend to think in for loops. I'm sure there exists a more concise and elegant solution. Any advice? Happy holidays, -david
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