# 因子的使用 -------------------------------------------------------------------
diabetes <- factor(diabetes)
View(diabetes)
status <- c('Poor','Improved','Excellent','Poor')
status <- factor(status, ordered = T)
status
status <- factor(status, ordered = T, levels = c("Poor",'Improved','Excellent')) #有序型指定顺序
status
sex <- c('Male','Female')
sex <- factor(sex, levels = c('Male','Female'))
sex <- factor(sex, levels = c('Male','Female'), ordered = TRUE)
sex <- factor(sex, levels = c(1,2),labels = c('Male','Female'))
#完整示例
##以向量形式输入数据
patientID <- c(1,2,3,4)
age <- c(25,34,28,52)
diabetes <- c('Type1','Type2','Type1','Type1')
status<-c('Poor','Improved','Excellent','Poor')
##因子化
diabetes = factor(diabetes)
status = factor(status, ordered = T)
patientdata = data.frame(patientID,age,diabetes,status)
str(patientdata) #数据结构
summary(patientdata) # 描述统计
