levels.factor              package:base              R Documentation

Factor Levels Assignment

Description:

     `levels<-' provides a way to alter the levels attribute of factor.
     `value' can be a vector of character strings with length equal to
     the number of levels of `x', or a named list specifying how to
     rename the levels.

Usage:

     levels(x) <- value

See Also:

     `factor', `levels', `levels<-', `nlevels'.

Examples:

     # assign individual levels
     x <- gl(2, 4, 8)
     levels(x)[1] <- "low"
     levels(x)[2] <- "high"

     # or as a group
     y <- gl(2, 4, 8)
     levels(y) <- c("low", "high")

     # combine some levels
     z <- gl(3, 2, 12)
     levels(z) <- c("A", "B", "A")

     # same, using a named list
     z <- gl(3, 2, 12)
     levels(z) <- list(A=c(1,3), B=2)

