Fast version of
as.POSIXct.character for GMT fixed format.
fastPOSIXct converts timestamps in textual (string) form into
POSIXct objects. It interprets sequences of digits
separated by non-digits as a timestamp in GMT. The order of
interpretation is fixed: year, month, day, hour, minute, second.
Note that only true (positive) POSIX dates (since 1970-01-01 00:00:00)
are supported and
fastPOSIXct accepts dates up to year 2199.
It is extremely fast (compared to
as.POSIXct by several orders
of magnitude (on some platfroms 1000x faster) since it uses pure text
parsing and no system calls.
fastPOSIXct(x, tz = NULL, required.components = 3L)
- string vector to interpret as timestamps
- timezone for the resulting
POSIXctobject - this is NOT the time of
x, that will always be GMT!
- minimum number of timestamp components that
are required. For example 3 means only the date is required, 6 means
all components (up to the seconds) are required. If the requirement
is not met, the result for that entry will be
Numeric vector of the class
POSIXct. In fact this function computes the numeric vector and calls
.POSIXctto create the result.
## let us generate a bunch of random timestamps until today ts <- as.character(.POSIXct(runif(1e4) * unclass(Sys.time()), "GMT")) ## convert them using as.POSIXct system.time(a <- as.POSIXct(ts, "GMT")) ## same using the fast method system.time(b <- fastPOSIXct(ts, "GMT")) identical(a, b)