| Title: | 'Rcpp' Bindings for the 'CCTZ' Library |
|---|---|
| Description: | 'Rcpp' Access to the 'CCTZ' timezone library is provided. 'CCTZ' is a C++ library for translating between absolute and civil times using the rules of a time zone. The 'CCTZ' source code, released under the Apache 2.0 License, is included in this package. See <https://github.com/google/cctz> for more details. |
| Authors: | Dirk Eddelbuettel |
| Maintainer: | Dirk Eddelbuettel <[email protected]> |
| License: | GPL (>= 2) |
| Version: | 0.2.12.1 |
| Built: | 2024-08-18 04:17:05 UTC |
| Source: | https://github.com/eddelbuettel/rcppcctz |
CCTZ contains two underlying libraries which build on the C++11
library chrono. The first covers civil time for
computing with human-scale time such as dates and time. It is
header-only. The second covers time zones and allow translation
between absolute time and civil time.
RcppCCTZ brings CCTZ to R by means of Rcpp.
CCTZ requires a valid timezone library as well as recent-enough compiler to cope with C++11.
Windows is supported since version 0.2.0 via the g++-4.9
compiler, but note that it provides an incomplete C++11
library. The std::get_time function was ported from libc++ of
the LLVM to enable this. However, string formatting is more limited as
the libc++ library used by g++-4.9 does not provide complete
C++11 semantics. As one example, CCTZ frequently uses "%F %T"
which do not work on Windows; one has to use
"%Y-%m-%d %H:%M:%S".
Dirk Eddelbuettel wrote the package; Dan Dillon ported std::get_time
from LLVM's libc++; Bradley White and Greg Miller wrote the underlying CCTZ library.
Maintainer: Dirk Eddelbuettel <[email protected]>
The CCZT repository at https://github.com/google/cctz has additional information.
helloMoon()helloMoon()
Format a Datetime vector
formatDatetime(dtv, fmt = "%Y-%m-%dT%H:%M:%E*S%Ez", lcltzstr = "UTC", tgttzstr = "UTC") formatDouble(secv, nanov, fmt = "%Y-%m-%dT%H:%M:%E*S%Ez", tgttzstr = "UTC")formatDatetime(dtv, fmt = "%Y-%m-%dT%H:%M:%E*S%Ez", lcltzstr = "UTC", tgttzstr = "UTC") formatDouble(secv, nanov, fmt = "%Y-%m-%dT%H:%M:%E*S%Ez", tgttzstr = "UTC")
dtv |
A Datetime vector object to be formatted |
fmt |
A string with the format, which is based on |
lcltzstr |
The local timezone object for creation the CCTZ timepoint |
tgttzstr |
The target timezone for the desired format |
secv |
A numeric vector with seconds since the epoch |
nanov |
A numeric vector with nanoseconds since the epoch,
complementing |
An alternative to format.POSIXct based on the CCTZ library. The
formatDouble variant uses two vectors for seconds since the epoch
and fractional nanoseconds, respectively, to provide fuller resolution.
A string vector with the requested format of the datetime objects
Windows is now supported via the g++-4.9 compiler, but note
that it provides an incomplete C++11 library. This means we had
to port a time parsing routine, and that string formatting is more
limited. As one example, CCTZ frequently uses "%F %T" which do
not work on Windows; one has to use "%Y-%m-%d %H:%M:%S".
Dirk Eddelbuettel
## Not run: now <- Sys.time() formatDatetime(now) # current (UTC) time, in full precision RFC3339 formatDatetime(now, tgttzstr="America/New_York") # same but in NY formatDatetime(now + 0:4) # vectorised ## End(Not run)## Not run: now <- Sys.time() formatDatetime(now) # current (UTC) time, in full precision RFC3339 formatDatetime(now, tgttzstr="America/New_York") # same but in NY formatDatetime(now + 0:4) # vectorised ## End(Not run)
Parse a Datetime vector
parseDatetime(svec, fmt = "%Y-%m-%dT%H:%M:%E*S%Ez", tzstr = "UTC") parseDouble(svec, fmt = "%Y-%m-%dT%H:%M:%E*S%Ez", tzstr = "UTC")parseDatetime(svec, fmt = "%Y-%m-%dT%H:%M:%E*S%Ez", tzstr = "UTC") parseDouble(svec, fmt = "%Y-%m-%dT%H:%M:%E*S%Ez", tzstr = "UTC")
svec |
A string vector from which a Datetime vector is to be parsed |
fmt |
A string with the format, which is based on |
tzstr |
The local timezone for the desired format |
An alternative to as.POSIXct based on the CCTZ library
A Datetime vector object for parseDatetime, a numeric matrix with
two columns for seconds and nanoseconds for parseDouble
Dirk Eddelbuettel
ds <- getOption("digits.secs") options(digits.secs=6) # max value parseDatetime("2016-12-07 10:11:12", "%Y-%m-%d %H:%M:%S") # full seconds parseDatetime("2016-12-07 10:11:12.123456", "%Y-%m-%d %H:%M:%E*S") # fractional seconds parseDatetime("2016-12-07T10:11:12.123456-00:00") ## default RFC3339 format parseDatetime("20161207 101112.123456", "%E4Y%m%d %H%M%E*S") # fractional seconds now <- trunc(Sys.time()) parseDatetime(formatDatetime(now + 0:4)) # vectorised options(digits.secs=ds)ds <- getOption("digits.secs") options(digits.secs=6) # max value parseDatetime("2016-12-07 10:11:12", "%Y-%m-%d %H:%M:%S") # full seconds parseDatetime("2016-12-07 10:11:12.123456", "%Y-%m-%d %H:%M:%E*S") # fractional seconds parseDatetime("2016-12-07T10:11:12.123456-00:00") ## default RFC3339 format parseDatetime("20161207 101112.123456", "%E4Y%m%d %H%M%E*S") # fractional seconds now <- trunc(Sys.time()) parseDatetime(formatDatetime(now + 0:4)) # vectorised options(digits.secs=ds)
Change from one given timezone to another.
toTz(dtv, tzfrom, tzto, verbose = FALSE)toTz(dtv, tzfrom, tzto, verbose = FALSE)
dtv |
A DatetimeVector object specifying when the difference is to be computed. |
tzfrom |
The first time zone as a character vector. |
tzto |
The second time zone as a character vector. |
verbose |
A boolean toggle indicating whether more verbose operations
are desired, default is |
Time zone offsets vary by date, and this helper function converts a Datetime object from one given timezone to another.
A DatetimeVector object with the given (civil time) determined by the incoming object (and its timezone) shifted to the target timezone.
Dirk Eddelbuettel
## Not run: toTz(Sys.time(), "America/New_York", "Europe/London") # this redoes the 'Armstrong on the moon in NYC and Sydney' example toTz(ISOdatetime(1969,7,20,22,56,0,tz="UTC"), "America/New_York", "Australia/Sydney", verbose=TRUE) # we can also explicitly format for Sydney time format(toTz(ISOdatetime(1969,7,20,22,56,0,tz="UTC"), "America/New_York", "Australia/Sydney", verbose=TRUE), tz="Australia/Sydney") ## End(Not run)## Not run: toTz(Sys.time(), "America/New_York", "Europe/London") # this redoes the 'Armstrong on the moon in NYC and Sydney' example toTz(ISOdatetime(1969,7,20,22,56,0,tz="UTC"), "America/New_York", "Australia/Sydney", verbose=TRUE) # we can also explicitly format for Sydney time format(toTz(ISOdatetime(1969,7,20,22,56,0,tz="UTC"), "America/New_York", "Australia/Sydney", verbose=TRUE), tz="Australia/Sydney") ## End(Not run)
Difference between two given timezones at a specified date.
tzDiff(tzfrom, tzto, dt, verbose = FALSE)tzDiff(tzfrom, tzto, dt, verbose = FALSE)
tzfrom |
The first time zone as a character vector. |
tzto |
The second time zone as a character vector. |
dt |
A Datetime object specifying when the difference is to be computed. |
verbose |
A boolean toggle indicating whether more verbose operations
are desired, default is |
Time zone offsets vary by date, and this helper function computes the difference (in hours) between two time zones for a given date time.
A numeric value with the difference (in hours) between the first and second time zone at the given date
Dirk Eddelbuettel
## Not run: # simple call: difference now tzDiff("America/New_York", "Europe/London", Sys.time()) # tabulate difference for every week of the year table(sapply(0:52, function(d) tzDiff("America/New_York", "Europe/London", as.POSIXct(as.Date("2016-01-01") + d*7)))) ## End(Not run)## Not run: # simple call: difference now tzDiff("America/New_York", "Europe/London", Sys.time()) # tabulate difference for every week of the year table(sapply(0:52, function(d) tzDiff("America/New_York", "Europe/London", as.POSIXct(as.Date("2016-01-01") + d*7)))) ## End(Not run)