how to read a csv with a timestamp field?
r
Solution
If you want to read the .csv file directly into a time series object, you can use the function `read.zoo()` from the `zoo` package. This internally calls `read.table()` (rather than `read.csv`) and then converts the specified time index column(s). See `?read.zoo` and `vignette("zoo-read", package = "zoo")`.
An example with time stamps like yours is:
csv <-
"x,y,timestamp
0,1,2014-12-01T18:54:22.973+0000
1,2,2014-12-01T19:43:11.862+0000"
read.zoo(text = csv, sep = ",", header = TRUE, index = "timestamp",
format = "%Y-%m-%dT%H:%M:%OS%z", tz = "GMT")
And this yields a `zoo` series with `POSIXct` time stamps:
x y
2014-12-01 18:54:22 0 1
2014-12-01 19:43:11 1 2
(Of course, the `text = csv` would have to be replaced by something like `file = "my.csv"` if you are reading a .csv file from the disk rather than a text string from within R.)
Problem
I'm trying to import a csv file that has a field `Ts` containing ISO8601 time stamp values (E.g. 2014-12-01T18:54:22.973+0000). I have seen that you can specify the class of columns: ``` kd <- read.csv( "my.csv", colClasses=c( "Ts"="?" )) ``` However, I can't find how to declare a timestamp field. Question: How can I specify that this field is a time stamp?