取此标题:
df <- tibble(station = c("station1","station2","station2","station2"),
data = c(list(tibble(timestamp = c("2001-01-01","2002-01-02", "2002-01-03"), value=c(1,2,3))),
list(tibble(timestamp = NA, value = NA)),
list(tibble(timestamp = c("2001-01-01","2002-01-02", "2002-01-03"), value=c(1,2,3))),
list(tibble(timestamp = c("2001-01-01","2002-01-02"), value=c(1,2)))))
我现在要按车站分组。对于每个组，我现在要在相关的嵌套标题中找到最后一个公共时间戳。
对于站点1，这将是"2002-01-03">
对于第二站，这将是"2002-01-02">
我怎么能得到这个结果?提前感谢!
df %>%
unnest(data) %>%
group_by(timestamp) %>%
filter(n_distinct(station) > 1) %>% # Get common timestamp across stations
group_by(station) %>%
summarise(last_common = last(timestamp)) # Get the last common timestamp
# A tibble: 2 × 2
station last_date
<chr> <chr>
1 station1 2002-01-03
2 station2 2002-01-02