我在 csv 文件中有一个不规则的时间序列(带有 DateTime 和 RainfallValue)C:\SampleData.csv
:
DateTime,RainInches
1/6/2000 11:59,0
1/6/2000 23:59,0.01
1/7/2000 11:59,0
1/13/2000 23:59,0
1/14/2000 0:00,0
1/14/2000 23:59,0
4/14/2000 3:07,0.01
4/14/2000 3:12,0.03
4/14/2000 3:19,0.01
12/31/2001 22:44,0
12/31/2001 22:59,0.07
12/31/2001 23:14,0
12/31/2001 23:29,0
12/31/2001 23:44,0.01
12/31/2001 23:59,0.01
注意:不规则的时间步长可以是 1 分钟、15 分钟、1 小时等。此外,在所需的 15 分钟间隔内可能会有多个观察。
我正在尝试创建一个从 2000-01-01 到 2001-12-31 的常规 15 分钟时间序列,应该如下所示:
2000-01-01 00:15:00 0.00
2000-01-01 00:30:00 0.00
2000-01-01 00:45:00 0.00
...
2001-12-31 23:30:00 0.01
2001-12-31 23:45:00 0.01
注意:时间序列以 15 分钟为间隔,将缺失的数据填充为 0。如果 15 分钟的间隔中有多个数据点,则将它们相加。
这是我的代码:
library(zoo)
library(xts)
filename = "C:\\SampleData.csv"
ReadData <- read.zoo(filename, format = "%m/%d/%Y %H:%M", sep=",", tz="UTC", header=TRUE) # read .csv as a ZOO object
RawData <- aggregate(ReadData, index(ReadData), sum) # Merge duplicate time stamps and SUM the corresponding data (CAUTION)
RawDataSeries <- as.xts(RawData,order.by =index(RawData)) #convert to an XTS object
RegularTimes <- seq(as.POSIXct("2000-01-01 00:00:00", tz = "UTC"), as.POSIXct("2001-12-31 23:45:00", tz = "UTC"), by = 60*15)
BlankTimeSeries <- xts((rep(0,length(RegularTimes))),order.by = RegularTimes)
MergedTimeSeries <- merge(RawDataSeries,BlankTimeSeries)
TS_sum15min <- period.apply(MergedTimeSeries,endpoints(MergedTimeSeries, "minutes", 15), sum, na.rm = TRUE )
TS_align15min <- align.time( TS_sum15min [endpoints(TS_sum15min , "minutes", 15)], n=60*15)
问题:输出时间序列TS_align15min
:(a)具有重复的时间戳块(b)从 1999 年开始(神秘地),如:
1999-12-31 19:15:00 0
1999-12-31 19:30:00 0
1999-12-31 19:45:00 0
1999-12-31 20:00:00 0
1999-12-31 20:15:00 0
1999-12-31 20:30:00 0
我究竟做错了什么?
感谢您的任何指导!