RcppCCTZ 0.0.4

April 17, 2016

(This article was first published on Thinking inside the box , and kindly contributed to R-bloggers)

A few days ago a new upstream version "2.0" of CCTZ was released. See here for the corresponding post on the Google OpenSource Blog.

CCTZ is a C++ library for translating between absolute and civil times using the rules of a time zone. It requires only a proper C++11 compiler and the standard IANA time zone data base which standard Unix, Linux, OS X, … computers tend to have in /usr/share/zoneinfo. RcppCCTZ connects this library to R by relying on Rcpp. This new version adds more support to the notion of civil time representation — i.e. independent of timezones — which can then be mapped to different time zone representations.

Changes in this version are summarized here:

Changes in version 0.0.4 (2016-04-17)

  • Synchronized with CCTZ v2 upstream.

  • Updated examples.cpp accordingly

A quick example is provided here where we look at the time when Neil Armstrong first stepped on the moon as an absolute ("civil") time and two local representations:

// from examples/hello.cc
// [[Rcpp::export]]
int helloMoon() {
    cctz::time_zone syd;
    if (!cctz::load_time_zone("Australia/Sydney", &syd)) return -1;

    // Neil Armstrong first walks on the moon
    const auto tp1 = cctz::convert(cctz::civil_second(1969, 7, 21, 12, 56, 0), syd);

    const std::string s = cctz::format("%F %T %z", tp1, syd);
    Rcpp::Rcout << s << "n";

    cctz::time_zone nyc;
    cctz::load_time_zone("America/New_York", &nyc);

    const auto tp2 = cctz::convert(cctz::civil_second(1969, 7, 20, 22, 56, 0), nyc);
    return tp2 == tp1 ? 0 : 1;

We can call this from R, and get the expected result (of equivalence between the dates):

R> library(RcppCCTZ)
R> helloMoon()
1969-07-21 12:56:00 +1000
[1] 0

We also have a diff to the previous version thanks to CRANberries.

More details, issue tickets etc at the GitHub repository.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

To leave a comment for the author, please follow the link and comment on their blog: Thinking inside the box .

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