combine_factor {reshape}

Combine factor levels

Description

Convenience function to make it easy to combine multiple levels

Usage

combine_factor(fac, variable=levels(fac), other.label="Other")

Arguments

fac

factor variable

variable

either a vector of . See examples for more details.

other.label

label for other level

Author(s)

Hadley Wickham <[e-mail]>

Examples

df <- data.frame(a = LETTERS[sample(5, 15, replace=TRUE)], y = rnorm(15))  
combine_factor(df$a, c(1,2,2,1,2))
combine_factor(df$a, c(1:4, 1))
(f <- reorder(df$a, df$y))
percent <- tapply(abs(df$y), df$a, sum)
combine_factor(f, c(order(percent)[1:3]))