使用 dplyr 包仅保留常见日期答案

【问题标题】：Keep only common dates using dplyr package使用 dplyr 包仅保留常见日期
【发布时间】：2023-01-14 22:28:39
【问题描述】：

我有一个包含 3 列的数据框：站点、日期时间和英里数。我想保留每个站具有共同日期时间的行。

为了更清楚，我创建了一个可重现的示例

library(tidyverse)
library(lubridate)

df <- data.frame(station = c("A","A","A","B","B","B",
                                  "C","C","C"),
  date = c("1998-05-03","1999-06-01","2000-03-02",
           "1998-05-03","1999-06-01","2000-03-02",
           "1998-05-03","1999-06-01","2000-04-15"),
                      time  = c("00:00:10","00:00:20","00:00:50",
                                "00:00:10","00:00:20","00:00:40",
                                "00:00:34","00:00:20","00:00:40"),
                      miles = rnorm(9))

df <- df %>% 
  mutate(datetime = paste(date,time,sep = " "),
         datetime = as_datetime(datetime)) %>% 
  select(station,datetime,miles)

station	datetime	miles
A	1998-05-03 00:00:10	1.8587913
A	1999-06-01 00:00:20	0.1271054
A	2000-03-02 00:00:50	1.4531250
B	1998-05-03 00:00:10	0.3544122
B	1999-06-01 00:00:20	0.1033785
B	2000-03-02 00:00:40	0.9861990
C	1998-05-03 00:00:34	1.5029350
C	1999-06-01 00:00:20	1.1215914
C	2000-04-15 00:00:40	0.5222949

理想的输出

station	datetime	miles
A	1998-05-03 00:00:10	1.8587913
A	1999-06-01 00:00:20	0.1271054
B	1998-05-03 00:00:10	0.3544122
B	1999-06-01 00:00:20	0.1033785
C	1999-06-01 00:00:20	1.1215914

我尝试了以下代码，但没有用：

df %>%
  filter(station %in% (split(df$station, df$datetime) %>% reduce(intersect)))

你有什么建议吗？（我更喜欢 dplyr 解决方案，但任何解决方案都可以接受）

【问题讨论】：

标签： r dplyr

【解决方案1】：

请尝试

df2 <- df %>% dplyr::arrange(date, time) %>% 
dplyr::group_by(date,time) %>% mutate(n=n()) %>% 
filter(n>1) %>% dplyr::arrange(station)

【讨论】：