r
group = c(rep("A", 5), rep("B", 5))
set.seed(1); age=c(sample(15:35, 10))
mydat = data.frame(group, age)
head(mydat)
tapply
r
tapply(age, group, mean, data=mydat)
그룹별(group) 평균(mean) 나이(age)
aggregate
r
aggregate(age~group, data=mydat, mean)
그룹별(group) 평균(mean) 나이(age)
