2018-12-04 阅读量: 589
x<-factor (c ("yes" , "yes" , "no", "yes" ) , ordered=T) ; x
## [1] yes yes no yes
## levels: no < yes
unclass (x)
## [1] 2 2 1 2
## attr(,"levels ")
## [1] "no" "yes”
table (x) #看每个等级的频数
## x
## no yes
## 1 3
x<- f actor (c (" yes" ,“yes ", "no", "yes") , level s=c (" yes" , "no") , ordered = T)
x #levels定义因子顺序 默认按字母顺序
## [1] yes yes no yes
## levels: yes < no
