combine_factor {reshape}R Documentation

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

Details

Author(s)

Hadley Wickham <h.wickham@gmail.com>

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_factor(df$a, tapply(df$y, df$a, mean)))
percent <- tapply(abs(df$y), df$a, sum)
combine_factor(f, c(order(percent)[1:3]))

[Package reshape version 0.7 Index]