根据映射关系查找替换

Replace values in a dataframe based on lookup table

https://www.codenong.com/35636315/

https://746923.com/r-use-data-frame-as-lookup-table

  根据以上网页的内容，  没有映射关系的，会被赋值NA，再替换NA。

  修改代码，一步到位。

  new <- data
  new[] <-
    lapply(data, function(x)
      ifelse(is.na(match(x, dmjm$dm)), x, dmjm$jm[match(x, dmjm$dm)]))

Note that I use empty brackets ([]) in couple cases until keep which structure of new as it used (a data.frame).