如果是这种，直接用duplicated函数，例如
set.seed(1234)
df <- data.frame(x1 = sample(c("Normal","Unnormal"), 10, replace = TRUE),
x2 = sample(c("a","b"), 10,replace = TRUE),
x3 = sample(c("c","d"), 10,replace = TRUE))
df
df[!duplicated(df[,-1]),] # 按第2,3列去重后的结果
如果是要去重且必须指定第一列值是“正常”，可以用dplyr包
library(dplyr)
df %>% group_by(x2,x3) %>% filter(x1 == "Normal" &row_number() == 1) %>% ungroup() #
那你就先把所有的字符串都变成小写，再用duplicated比较就好了x<-c("Anne","anne","bkk")
y<-tolower(x)
duplicated(y)
