I want a function that does the opposite of max.col() (which would be min.col)

There is an answer for this, but I don´t really understand it. Could anybody give a different solution?

CodePudding user response：

Negate the columns. Using BOD which comes with R:

max.col(BOD)
## [1] 2 2 2 2 2 2

max.col(-BOD)
## [1] 1 1 1 1 1 1

If the data frame is not numeric use xtfrm first

DF <- data.frame(X = c("a", "b", "a"), Y = c("b", "a", "b"))
max.col(-t(apply(DF, 1, xtfrm)))
## [1] 1 2 1