Recode variables

wants <- c("car", "DescTools")
has   <- wants %in% rownames(installed.packages())
if(any(!has)) install.packages(wants[!has])

myColors <- c("red", "purple", "blue", "blue", "orange", "red", "orange")
farben   <- character(length(myColors))
farben[myColors == "red"]    <- "rot"
farben[myColors == "purple"] <- "violett"
farben[myColors == "blue"]   <- "blau"
farben[myColors == "orange"] <- "orange"
farben

replace(c(1, 2, 3, 4, 5), list=c(2, 4), values=c(200, 400))

library(car)
recode(myColors, "'red'='rot'; 'blue'='blau'; 'purple'='violett'")

recode(myColors, "c('red', 'blue')='basic'; else='complex'")

orgVec <- c(5, 9, 11, 8, 9, 3, 1, 13, 9, 12, 5, 12, 6, 3, 17, 5, 8, 7)
cutoff <- 10
(reVec <- ifelse(orgVec <= cutoff, orgVec, cutoff))

targetSet <- c("A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K")
response  <- c("Z", "E", "O", "W", "H", "C", "I", "G", "A", "O", "B")
(respRec  <- ifelse(response %in% targetSet, response, "other"))

set.seed(123)
IQ <- rnorm(20, mean=100, sd=15)
ifelse(IQ >= 100, "hi", "lo")

library(car)
recode(IQ, "0:100=1; 101:115=2; else=3")

IQfac <- cut(IQ, breaks=c(0, 85, 115, Inf), labels=c("lo", "mid", "hi"))
head(IQfac)

medSplit <- cut(IQ, breaks=c(-Inf, median(IQ), Inf))
summary(medSplit)

IQdiscr <- cut(IQ, quantile(IQ), include.lowest=TRUE)
summary(IQdiscr)

(status <- factor(c("hi", "lo", "hi")))

status[4] <- "mid"
status

levels(status) <- c(levels(status), "mid")
status[4] <- "mid"
status

hiNotHi <- status
levels(hiNotHi) <- list(hi="hi", notHi=c("mid", "lo"))
hiNotHi

library(car)
(statNew <- recode(status, "'hi'='high'; c('mid', 'lo')='notHigh'"))

status[1:2]

(newStatus <- droplevels(status[1:2]))

(facGrp <- factor(rep(LETTERS[1:3], each=5)))

library(DescTools)
(facRe <- reorder.factor(facGrp, new.order=c("C", "B", "A")))

vec <- rnorm(15, rep(c(10, 5, 15), each=5), 3)
tapply(vec, facGrp, FUN=mean)

reorder(facGrp, vec, FUN=mean)

try(detach(package:car))
try(detach(package:DescTools))