r - 调整输出表中的日期顺序

Question

输出表的顺序不正确，01/01之后变成01/02而不是03/01，如何调整？

 df1<- structure(
  list(date2= c("01-01-2021","01-01-2021","03-01-2021","03-01-2021","01-02-2021","01-02-2021"),
       Category= c("ABC","CDE","ABC","CDE","ABC","CDE"),
       coef= c(5,4,0,2,4,5)),
  class = "data.frame", row.names = c(NA, -6L))

x<-df1 %>%
  group_by(date2) %>%
  summarize(across("coef", sum),.groups = 'drop')

> x
# A tibble: 3 x 2
  date2       coef
  <chr>      <dbl>
1 01-01-2021     9
2 01-02-2021     9
3 03-01-2021     2

预期输出表

  date2       coef
      <chr>      <dbl>
    1 01-01-2021     9
    2 03-01-2021     2
    3 01-02-2021     9

如果我有以下代码:

df1<- structure(
  list(date2= c("01-01-2022","01-01-2022","03-01-2021","03-01-2021","01-02-2021","01-02-2021"),
       Category= c("ABC","CDE","ABC","CDE","ABC","CDE"),
       coef= c(5,4,0,2,4,5)),
  class = "data.frame", row.names = c(NA, -6L))

x<-df1 %>%
  group_by(date2) %>%
  summarize(across("coef", sum),.groups = 'drop')%>% 
  arrange(date2 = as.Date(date2, format = "%d-%m-%y"))

> x
# A tibble: 3 x 2
  date2       coef
  <chr>      <dbl>
1 01-01-2022     9
2 03-01-2021     2
3 01-02-2021     9
      

此顺序不正确，因为 01-01-2022 必须是最后一个而不是第一个。

Answer 1

您可以将日期列转换为日期格式，并对其进行排列。我还建议您对日期列使用日期格式，以便将来进行数据处理。

基础R

x$date2 <- as.Date(x$date2, format = "%d-%m-%Y")
x[order(x$date2),]

dplyr

x %>% 
  arrange(date2 = as.Date(date2, format = "%d-%m-%Y")

# A tibble: 3 x 2
  date2       coef
  <chr>      <dbl>
1 01-01-2021     9
2 03-01-2021     2
3 01-02-2021     9