使用dplyr的单位不一致

2024-05-07 • 问答

我不确定我是否做错了什么，但是我注意到，如果我尝试使用dplyr汇总包含持续时间数据的数据，则返回的单位不一致/不正确。为什么总结得出错误的单位？

library(lubridate)
time1 <- as.POSIXct("2018-06-27 12:08 AM")
time2 <- as.POSIXct("2018-02-15 16:33:58")

a <- data.frame(
  time = time1 + 1:3600 * 60
)

b <- data.frame(
  time = time2 + 1:3600 * 3600
)

c <- bind_rows(a,b,.id = "group")

# Units are incorrect
c %>%
  group_by(group) %>%
  summarise(
    median(diff(time))
  )

# They should look more like this
aggregate(time ~ group,data = c,FUN = function(x) median(diff(x)))
aggregate(time ~ group,FUN = function(x) units(median(diff(x))))

library(dplyr) c %>% group_by(group) %>% summarise( Median = median(difftime(time,lag(time,default = first(time)),unit = "min"))) # A tibble: 2 x 2 # group Median # <chr> <drtn> #1 1 1 mins #2 2 60 mins

使用dplyr的单位不一致

tingting04 回答：使用dplyr的单位不一致

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