R语言使用dplyr生成表格时星期排序错误，如何调整输出顺序

错误原因 #

你使用match函数做匹配时，传入的参考日期只有2021-11-07（周日）、2021-11-13（周六）两个值，调用weekdays()后得到的参考匹配向量仅有["周日", "周六"]两个元素：

• 周日匹配后返回值为1，排序第一位
• 周六匹配后返回值为2，排序第二位
• 其余周一到周五的星期值在参考向量中不存在，match返回NA，排序时默认排在非NA值之后，所以呈现出你看到的错误顺序。

修正方案 #

生成从起始日期到结束日期的完整7天日期序列作为匹配参考，即可得到周日到周六的完整排序优先级，修正后的代码如下：

library(dplyr)

Test <- structure(list(date1 = as.Date(c("2021-11-01","2021-11-01","2021-11-01","2021-11-01","2021-11-01","2021-11-01","2021-11-01")),
                      date2 = as.Date(c("2021-10-18","2021-10-19","2021-10-20","2021-10-21","2021-10-22","2021-10-23","2021-10-24")),
                       Week = c("Monday", "Tuesday", "Wednesday", "Thursday","Friday","Saturday","Sunday"),
                      Category = c("FDE", "FDE", "FDE", "FDE","FDE","FDE","FDE"),
                       time = c(4, 6, 3, 2,3,3,4)), class = "data.frame",row.names = c(NA, -7L))

wk_port2eng <- data.frame(
  WeekE = c("Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"),
  WeekP = c("segunda-feira", "terca-feira", "quarta-feira", "quinta-feira",  "sexta-feira", "sabado", "domingo")
)

# 核心修改：生成完整7天日期序列作为匹配参考
left_join(Test, wk_port2eng, by = c("Week" = "WeekE")) %>%      
  arrange(match(WeekP, weekdays(seq.Date(as.Date("2021-11-07"), as.Date("2021-11-13"), by = "1 day")))) %>%
  select(-WeekP)

运行结果 #

date1      date2      Week Category time
1 2021-11-01 2021-10-24    Sunday      FDE    4
2 2021-11-01 2021-10-18    Monday      FDE    4
3 2021-11-01 2021-10-19   Tuesday      FDE    6
4 2021-11-01 2021-10-20 Wednesday      FDE    3
5 2021-11-01 2021-10-21  Thursday      FDE    2
6 2021-11-01 2021-10-22    Friday      FDE    3
7 2021-11-01 2021-10-23  Saturday      FDE    3

内容的提问来源于stack exchange，提问作者Antonio