检查Posixct时间是否在区间内

Check if Posixct time is within interval

问题: 我有两个要合并的数据帧,具体取决于一个数据帧的 date/time 在另一个数据帧的间隔内。

交通:日期和时间 (Posixct),频率

mydata:区间,频率之和

我现在想计算来自流量的 Posixct 时间是否在 mydata 的间隔内,如果这是 TRUE,我想计算 mydata 中 "Sum of Frequencies" 列中的频率。

我遇到的两个问题: 1. traffic 数据框的行数明显多于 mydata。我不知道如何告诉 R 遍历流量中的每个观察以检查 mydata 中的一行。

  1. mydata的频率区间内可以有多个观测拟合。我希望 R 将不同交通观察的所有频率相加以获得频率总分。间隔也是重叠的。

这是数据:

DateTime <- c("2014-11-01 04:00:00", "2014-11-01 04:03:00",  "2014-11-01 04:06:00", "2014-11-01 04:08:00", "2014-11-01 04:10:00", "2014-11-01 04:12:00", "2015-08-01 04:13:00", "2015-08-01 04:45:00", "2015-08-01 14:15:00", "2015-08-01 14:13:00")
DateTime <- as.POSIXct(DateTime)
Frequency <- c(1,2,3,5,12,1,2,2,1,1)                 
traffic <- data.frame(DateTime, Frequency)

library(lubridate)
DateTime1 <- c("2014-11-01 04:00:00", "2015-08-01 04:03:00",  "2015-08-01 14:00:00")
DateTime2 <- c("2014-11-01 04:15:00", "2015-08-01 04:13:00",  "2015-08-01 14:15:00")
DateTime1 <- as.POSIXct(DateTime1)
DateTime2 <- as.POSIXct(DateTime2)
mydata <- data.frame(DateTime1, DateTime2)
mydata$Interval <- as.interval(DateTime1, DateTime2)
mydata$SumFrequency <- NA

预期的结果应该是这样的:

mydata$SumFrequency <- c(24, 2, 2)
head(mydata)

我尝试了 int_overlaps 软件包 lubridate。 非常感谢有关如何解决此问题的任何提示!

就第 2 点而言,您可以使用聚合

aggData <- aggregate(traffic$Frequency~format(traffic$DateTime, "%Y%m%d h:m"), data=traffic, sum)

这会以分钟为间隔对所有频率求和。

对于第 1 点。合并行不通吗?

merge(x = myData, y = aggData, by = "DateTime", all.x = TRUE)  

外部合并解释here

使用 for.loop 我们可以这样做:

for(i in 1:nrow(mydata)) {
  mydata$SumFrequency[i] <- sum(traffic$Frequency[traffic$DateTime %within% mydata$Interval[i]])
}

> mydata
#            DateTime1           DateTime2                                           Interval SumFrequency
#1 2014-11-01 04:00:00 2014-11-01 04:15:00   2014-11-01 04:00:00 CET--2014-11-01 04:15:00 CET           24
#2 2015-08-01 04:03:00 2015-08-01 04:13:00 2015-08-01 04:03:00 CEST--2015-08-01 04:13:00 CEST            2
#3 2015-08-01 14:00:00 2015-08-01 14:15:00 2015-08-01 14:00:00 CEST--2015-08-01 14:15:00 CEST            2

我看到两个解决方案:

data.frameplyr

您可以使用 lubridate 中的 %within% 函数并使用 for 循环或使用 plyr 循环函数(例如 dlply

DateTime <- c("2014-11-01 04:00:00", "2014-11-01 04:03:00",  "2014-11-01 04:06:00", "2014-11-01 04:08:00", "2014-11-01 04:10:00", "2014-11-01 04:12:00", "2015-08-01 04:13:00", "2015-08-01 04:45:00", "2015-08-01 14:15:00", "2015-08-01 14:13:00")
DateTime <- as.POSIXct(DateTime)
Frequency <- c(1,2,3,5,12,1,2,2,1,1)                 
traffic <- data.frame(DateTime, Frequency)

library(lubridate)
DateTime1 <- c("2014-11-01 04:00:00", "2015-08-01 04:03:00",  "2015-08-01 14:00:00")
DateTime2 <- c("2014-11-01 04:15:00", "2015-08-01 04:13:00",  "2015-08-01 14:15:00")
DateTime1 <- as.POSIXct(DateTime1)
DateTime2 <- as.POSIXct(DateTime2)
mydata <- data.frame(DateTime1, DateTime2)
mydata$Interval <- as.interval(DateTime1, DateTime2)

library(plyr)
# Create a group-by variable
mydata$NumInt <- 1:nrow(mydata)
mydata$SumFrequency <- dlply(mydata, .(NumInt),
                             function(row){
                               sum(
                                 traffic[traffic$DateTime %within% row$Interval, "Frequency"]
                               )
                             })

mydata
#>             DateTime1           DateTime2
#> 1 2014-11-01 04:00:00 2014-11-01 04:15:00
#> 2 2015-08-01 04:03:00 2015-08-01 04:13:00
#> 3 2015-08-01 14:00:00 2015-08-01 14:15:00
#>                                             Interval NumInt SumFrequency
#> 1   2014-11-01 04:00:00 CET--2014-11-01 04:15:00 CET      1           24
#> 2 2015-08-01 04:03:00 CEST--2015-08-01 04:13:00 CEST      2            2
#> 3 2015-08-01 14:00:00 CEST--2015-08-01 14:15:00 CEST      3            2

具有 data.table 和函数 foverlaps

data.table 已经实现了重叠连接的功能,您可以通过一些小技巧在您的案例中使用它。
这个函数是foverlaps(我下面用的是data.table 1.9.6
(参见 How to perform join over date ranges using data.table? and this presentation

请注意,您不需要使用 lubridate

创建间隔
DateTime <- c("2014-11-01 04:00:00", "2014-11-01 04:03:00",  "2014-11-01 04:06:00", "2014-11-01 04:08:00", "2014-11-01 04:10:00", "2014-11-01 04:12:00", "2015-08-01 04:13:00", "2015-08-01 04:45:00", "2015-08-01 14:15:00", "2015-08-01 14:13:00")
DateTime <- as.POSIXct(DateTime)
Frequency <- c(1,2,3,5,12,1,2,2,1,1)                 
traffic <- data.table(DateTime, Frequency)

library(lubridate)
DateTime1 <- c("2014-11-01 04:00:00", "2015-08-01 04:03:00",  "2015-08-01 14:00:00")
DateTime2 <- c("2014-11-01 04:15:00", "2015-08-01 04:13:00",  "2015-08-01 14:15:00")
mydata <- data.table(DateTime1 = as.POSIXct(DateTime1), DateTime2 = as.POSIXct(DateTime2))

# Use function `foverlaps`  for overlapping joins

# Here's the trick : create a dummy variable to artificially have an interval
traffic[, dummy:=DateTime]
setkey(mydata, DateTime1, DateTime2)

# do the join
mydata2 <- foverlaps(traffic, mydata, by.x=c("DateTime", "dummy"), type ="within", nomatch=0L)[, dummy := NULL][]
mydata2
#>              DateTime1           DateTime2            DateTime Frequency
#> 1: 2014-11-01 04:00:00 2014-11-01 04:15:00 2014-11-01 04:00:00         1
#> 2: 2014-11-01 04:00:00 2014-11-01 04:15:00 2014-11-01 04:03:00         2
#> 3: 2014-11-01 04:00:00 2014-11-01 04:15:00 2014-11-01 04:06:00         3
#> 4: 2014-11-01 04:00:00 2014-11-01 04:15:00 2014-11-01 04:08:00         5
#> 5: 2014-11-01 04:00:00 2014-11-01 04:15:00 2014-11-01 04:10:00        12
#> 6: 2014-11-01 04:00:00 2014-11-01 04:15:00 2014-11-01 04:12:00         1
#> 7: 2015-08-01 04:03:00 2015-08-01 04:13:00 2015-08-01 04:13:00         2
#> 8: 2015-08-01 14:00:00 2015-08-01 14:15:00 2015-08-01 14:15:00         1
#> 9: 2015-08-01 14:00:00 2015-08-01 14:15:00 2015-08-01 14:13:00         1

# summarise with a sum by grouping by each line of mydata
setkeyv(mydata2, key(mydata))
mydata2[mydata, .(SumFrequency = sum(Frequency)), by = .EACHI]
#>              DateTime1           DateTime2 SumFrequency
#> 1: 2014-11-01 04:00:00 2014-11-01 04:15:00           24
#> 2: 2015-08-01 04:03:00 2015-08-01 04:13:00            2
#> 3: 2015-08-01 14:00:00 2015-08-01 14:15:00            2

data.table 方法 between 按时过滤交通数据集:

setDT(traffic)
setDT(mydata)

mydata[,SumFrequency := as.numeric(SumFrequency)] # coerce logical to numeric for next step.
mydata[,SumFrequency := sum( traffic[ DateTime %between% c(DateTime1, DateTime2), Frequency] ), by=1:nrow(mydata)] 

给出:

             DateTime1           DateTime2                                           Interval SumFrequency
1: 2014-11-01 04:00:00 2014-11-01 04:15:00   2014-11-01 04:00:00 CET--2014-11-01 04:15:00 CET           24
2: 2015-08-01 04:03:00 2015-08-01 04:13:00 2015-08-01 04:03:00 CEST--2015-08-01 04:13:00 CEST            2
3: 2015-08-01 14:00:00 2015-08-01 14:15:00 2015-08-01 14:00:00 CEST--2015-08-01 14:15:00 CEST            2

如果mydata中有很多行,最好创建一个索引列并在by子句中使用它:

mydata[, idx := .I]
mydata[, SumFrequency := sum( traffic[DateTime %between% c(DateTime1, DateTime2),Frequency] ),by=idx]

这给出了:

             DateTime1           DateTime2                                           Interval SumFrequency idx
1: 2014-11-01 04:00:00 2014-11-01 04:15:00   2014-11-01 04:00:00 CET--2014-11-01 04:15:00 CET           24   1
2: 2015-08-01 04:03:00 2015-08-01 04:13:00 2015-08-01 04:03:00 CEST--2015-08-01 04:13:00 CEST            2   2
3: 2015-08-01 14:00:00 2015-08-01 14:15:00 2015-08-01 14:00:00 CEST--2015-08-01 14:15:00 CEST            2   3

来自 data.table 包的 foverlaps 的简短解决方案:

mydata <- data.table(DateTime1, DateTime2, key = c("DateTime1", "DateTime2"))
traffic <- data.table(start = DateTime, end = DateTime, Frequency, key = c("start","end"))

foverlaps(traffic, mydata, type="within", nomatch=0L)[, .(sumFreq = sum(Frequency)), 
                                                      by = .(DateTime1, DateTime2)]

给出:

             DateTime1           DateTime2 sumFreq
1: 2014-11-01 04:00:00 2014-11-01 04:15:00      24
2: 2015-08-01 04:03:00 2015-08-01 04:13:00       2
3: 2015-08-01 14:00:00 2015-08-01 14:15:00       2