R - How to get max() to return variable names instead of contents of the variables?

Question

I need to find the max value from a list of variables. However, max() returns the contents of the variable instead of the variable name. Is there a way to get the name instead of the content?

Quick example code:

jan <- 0
feb <- 0
mar <- 0

#for testing purposes - just select a random month and add 10
s1 <- sample(1:3, 1)
if (s1==1) {
  jan <- jan + 10
}
if (s1==2) {
  feb <- feb + 10
}
if (s1==3) {
  mar <- mar + 10
}

final <- max(jan, feb, mar)

final

The result from that will always be 10. That isn't helpful... Is there a way to get the month/variable name returned instead? (ie "jan" instead of "10")

Thank you!

I also tried adding labels to the list, but the labels are not carried over with max() — jdfinch3, Oct 19 '14 at 08:04
You can name your vector elements to begin with, e.g.: `jan <- c(jan=0); feb <- c(feb=0); mar <- c(mar=0)`, and then `final <- which.max(jan, feb, mar)` will also be named. Access with `names(final)`. — jbaums, Oct 19 '14 at 08:22

score 8 · Accepted Answer · answered Oct 19 '14 at 08:19

8

You could try:

 c("jan", "feb", "mar")[which.max(c(jan, feb, mar))]
 #[1] "jan"

answered Oct 19 '14 at 08:19

akrun

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Thank you - this works perfectly. I had tried subsetting but apparently had something wrong... – jdfinch3 Oct 19 '14 at 08:37
@jdfinch3 Glad to know it works. Could you show the code for subsetting in your post. – akrun Oct 19 '14 at 08:40
Sorry, it's long since deleted as it didn't work. I believe I had the order backwards. Thanks. :) – jdfinch3 Oct 19 '14 at 20:44

R - How to get max() to return variable names instead of contents of the variables?

1 Answers1