Question

我有这个时间序列数据：

     "timestamp"          "depth" "from_sensor_to_river_bottom" "Depth_from_river_surface_to_bottom"
"1" "2012-05-23 18:30:12-05" 16.4 17.16 0.760000000000002
"2" "2012-05-23 18:15:08-05" 16.38 17.16 0.780000000000001
"3" "2012-05-23 18:00:03-05" 16.39 17.16 0.77
"4" "2012-05-23 17:45:13-05" 16.35 17.16 0.809999999999999
"5" "2012-05-23 17:30:08-05" 16.37 17.16 0.789999999999999

我使用以下代码：

d <- read.table(Name[1], header=TRUE)  #Name[1] is text file containing data

d <- read.zoo(d,
 format="'%Y-%m-%d %H:%M:%S'", 
 FUN=as.POSIXct  )

它给了我这个错误：

Error in read.zoo(d, format = "'%Y-%m-%d %H:%M:%S'", FUN = as.POSIXct) : 
 index has 5 bad entries at data rows: 1 2 3 4 5

我希望得到有关此问题的帮助。谢谢你的考虑。

Answer 1

您的时间戳数据包含格式错误的时区数据，即每个时间戳的-05个结尾。

从?strptime我了解到，您可以使用%z格式化已签名的时区偏移量，该偏移量应为有符号的四位数字，例如-0500。

%z
Signed offset in hours and minutes from UTC, so -0800 is 8 hours behind UTC.

因此，这是一种解决方法，可将缺少的00添加到您的时间戳中：

重新创建数据：

dat <- '
"timestamp" "depth" "from_sensor_to_river_bottom" "Depth_from_river_surface_to_bottom"
"1" "2012-05-23 18:30:12-05" 16.4 17.16 0.760000000000002
"2" "2012-05-23 18:15:08-05" 16.38 17.16 0.780000000000001
"3" "2012-05-23 18:00:03-05" 16.39 17.16 0.77
"4" "2012-05-23 17:45:13-05" 16.35 17.16 0.809999999999999
"5" "2012-05-23 17:30:08-05" 16.37 17.16 0.789999999999999
'

添加缺失的零：

x <- read.table(text=dat, header=TRUE)
x$timestamp <- paste(x$timestamp, "00", sep="")
x$timestamp <- as.POSIXct(x$timestamp, format="%Y-%m-%d %H:%M:%S%z")
x

转换为动物园

library(zoo)
as.zoo(x)
  timestamp           depth from_sensor_to_river_bottom Depth_from_river_surface_to_bottom
1 2012-05-24 00:30:12 16.40 17.16                       0.76                              
2 2012-05-24 00:15:08 16.38 17.16                       0.78                              
3 2012-05-24 00:00:03 16.39 17.16                       0.77                              
4 2012-05-23 23:45:13 16.35 17.16                       0.81                              
5 2012-05-23 23:30:08 16.37 17.16                       0.79

Answer 2

这适用于帖子中的数据，可以忽略每个日期/时间结束时的-05。（要从文件中读取，请使用注释掉的行。）

Lines <- '"timestamp"          "depth" "from_sensor_to_river_bottom" "Depth_from_river_surface_to_bottom"
"1" "2012-05-23 18:30:12-05" 16.4 17.16 0.760000000000002
"2" "2012-05-23 18:15:08-05" 16.38 17.16 0.780000000000001
"3" "2012-05-23 18:00:03-05" 16.39 17.16 0.77
"4" "2012-05-23 17:45:13-05" 16.35 17.16 0.809999999999999
"5" "2012-05-23 17:30:08-05" 16.37 17.16 0.789999999999999'

library(zoo)
# z <- read.zoo("myfile.txt", tz = "")
z <- read.zoo(text = Lines, tz = "")

以上代码的输出是：

> z
                    depth from_sensor_to_river_bottom Depth_from_river_surface_to_bottom
2012-05-23 17:30:08 16.37                       17.16                               0.79
2012-05-23 17:45:13 16.35                       17.16                               0.81
2012-05-23 18:00:03 16.39                       17.16                               0.77
2012-05-23 18:15:08 16.38                       17.16                               0.78
2012-05-23 18:30:12 16.40                       17.16                               0.76

有关详细信息，请尝试?read.zoo和?read.table以及vignette("zoo-read")。最后一篇是关于提供read.zoo示例的整个文档。

编辑：添加了评论链接。

如何在xts中阅读时间序列？

2 个答案: