用最常见的值替换数据输入错误 - dplyr

Question

我有一个数据框，其中包含一些数据输入错误。

我希望将每组的这些异常值替换为每组最常见的值。

我的数据如下:

df <- data.frame(CODE = c("J1745","J1745","J1745","J1745","J1100","J1100","J1100","J1100","J1100","J1100"),NDC = c(1234,1234,1234,1234,5678,5678,5678,5678,5678,5678),DOSAGE = c("10ML","10 ML","10 ML","10 ML","5 ML","5 ML","5 ML","5 ML","50 ML","5 ML"),DESC = c("TEXT1","TEXT 1","TEXT 1","TEXT 1","TEXT 2","TEXT 2","TEXT 2","TEXT 2","TEXT 10","TEXT 2"))

正如您所看到的，我的 DOSAGE 和 DESC 列包含一些不一致的地方，我想将它们替换为每组中最常见的值。

我想要的输出如下:

Answer 1

我同意这有潜在危险的评论。

下面的代码将出现次数 <= 指定次数的元素替换为最常见的值。我在替换函数中使用 base-R 机制，因为这是我知道该怎么做的。

repl_common <- function(x,n=1) {
    tt <- tapply(x,x,length)          ## count number of instances
    m <- names(tt)[which.max(tt)]     ## find mode
    x[tt[as.character(x)]<=n] <- m    ## replace
    return(x)
}
## apply by group across specified columns
df %>% group_by(CODE) %>% mutate(across(c(DOSAGE,DESC), repl_common))