#删去data表中第五列
data<- data[,-5]
#删去某几列
data <- data[,-c(6:9)]
#subset
data <- subset(data,select=-c(colnames5))
data <- subset(data,select=- c(colname6:colname9))
data1 <- subset(base_data,select=- c(6:9))
#“+”则是把需要的选出来
#一个稍微比较麻烦的形式，通过列名删除
data<- data[,!names(data) %in% c("sbp_m1","sbp_a1","dbp_m1","dbp_a1")]