我有一个数据帧,看起来像这样:
POI LOCAL.DATETIME
1 1 2017-07-11 15:02:13
2 1 2017-07-11 15:20:28
3 2 2017-07-11 15:20:31
4 2 2017-07-11 15:21:13
5 3 2017-07-11 15:21:18
6 3 2017-07-11 15:21:21
7 2 2017-07-11 15:21:25
8 2 2017-07-11 15:21:59
9 1 2017-07-11 15:22:02
10 1 2017-07-11 15:22:05我希望能够计算(可能使用lubridate)在每个POI上花费的累积时间,并将它们合并到一个类似于以下内容的表中:
POI TOTAL.TIME
1 1 00:18:18
2 2 00:01:11
3 3 00:00:03此外,我不确定如何处理POI之间的时间,如第2行和第3行之间的3秒。我认为我可能需要计算第1行到第3行的时间,而不是第1行到第2行的时间。
发布于 2017-07-14 03:52:18
要获取每个组周期内的总时间,首先需要创建一个组索引。我正在使用data.table中的rleid,然后您可以计算在每个组中花费的总时间,然后使用sum汇总初始POI。
df <- read.table(text=" POI LOCAL.DATETIME
1 '2017-07-11 15:02:13'
1 '2017-07-11 15:20:28'
2 '2017-07-11 15:20:31'
2 '2017-07-11 15:21:13'
3 '2017-07-11 15:21:18'
3 '2017-07-11 15:21:21'
2 '2017-07-11 15:21:25'
2 '2017-07-11 15:21:59'
1 '2017-07-11 15:22:02'
1 '2017-07-11 15:22:05'",
header=TRUE,stringsAsFactors=FALSE)
df$LOCAL.DATETIME <- as.POSIXct(df$LOCAL.DATETIME)
library(dplyr)
df%>%
mutate(grp=data.table::rleid(POI))%>%
group_by(grp)%>%
summarise(POI=max(POI),TOTAL.TIME=difftime(max(LOCAL.DATETIME),
min(LOCAL.DATETIME),units="secs"))%>%
group_by(POI)%>%
summarise(TOTAL.TIME=sum(TOTAL.TIME))
# A tibble: 3 × 2
POI TOTAL.TIME
<int> <time>
1 1 1098 secs
2 2 76 secs
3 3 3 secs要获取分钟和秒,可以使用lubridate中的as.period
library(lubridate)
df%>%
mutate(grp=data.table::rleid(POI))%>%
group_by(grp)%>%
summarise(POI=max(POI),TOTAL.TIME=difftime(max(LOCAL.DATETIME),
min(LOCAL.DATETIME),units="secs"))%>%
group_by(POI)%>%
summarise(TOTAL.TIME=sum(TOTAL.TIME))%>%
mutate(TOTAL.TIME =as.period((TOTAL.TIME), unit = "sec"))
POI TOTAL.TIME
<int> <S4: Period>
1 1 18M 18S
2 2 1M 16S
3 3 3S发布于 2017-07-14 04:29:13
另一个data.table选项是为每个POI创建两行的分组,取它们之间的时间差,最后用POI求和
library(data.table)
dt <- as.data.table(df)
dt[, grp2 := (seq_len(.N)+1) %/% 2, by = POI]
dt[, time_diff := difftime(LOCAL.DATETIME, shift(LOCAL.DATETIME), unit = "min"), by = .(POI, grp2)]
dt[ , .(TOTAL.TIME = sum(time_diff, na.rm = T)), by = POI]
# POI TOTAL.TIME
#1: 1 18.300000 mins
#2: 2 1.266667 mins
#3: 3 0.050000 minshttps://stackoverflow.com/questions/45089710
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