faraway, chapter 5, p.98
library(faraway) # p.98 data(nes96) head(nes96) sPID <- nes96$PID levels(sPID) # [1] "strDem" "weakDem" "indDem" "indind" "indRep" "weakRep" "strRep" levels(sPID) <- c("Democrat", "Democrat", "Independent", "Independent", "Independent", "Republican", "Republican")