On 16 March 2014 at 22:24, Sandip Nandi wrote:
| Hi Bill ,
|
| The following C code may help you , time_t is typedef to long int
|
| SEXP getTime() {
|
| time_t current_time;
| char* c_time_string;
| current_time = time(NULL);
| c_time_string = ctime(¤t_time);
|
| return mkString(c_time_String); // or if you want to return as int vector
| return scalarInt(current_time);
| }
|
| If you feel anything wrong , I will be very happy to know .
That is a) time and not date, and b) formatted as a string.
Dirk
| Thanks,
| Sandip
|
|
| On Sun, Mar 16, 2014 at 9:54 PM, Bill Wang <freecn...@gmail.com> wrote:
|
| Hi Dirk,
|
| Thanks for your reply, I neede convert time_t to R type in C code, can not
| use Rcpp. Maybe Rcpp source code could help me.
|
| Cheers,
| Bill
|
|
| 2014-03-16 22:55 GMT+08:00 Dirk Eddelbuettel <e...@debian.org>:
|
| >
| > On 16 March 2014 at 18:36, Bill Wang wrote:
| > | I am writing a R extensions, and I need pass time_t to R in C, but I
| > don't
| > | know how to do.
| > | Can you give me some help? do not use double directly.
| >
| > Just treat it as an int:
| >
| > R> library(Rcpp)
| > R> cppFunction("Date time_t2date(time_t what) { return((int) what); }
| ")
| > R> time_t2date(0)
| > [1] "1970-01-01"
| > R> time_t2date( Sys.Date() )
| > [1] "2014-03-16"
| > R>
| >
| >
| > Here I use Rcpp to define the 'time_t2date' function on the fly.
| >
| > It takes the time_t and returns a Date type (which here is a C++ Date
| type
| > mapping to the R Date -- you can ignore that, but will have to write the
| > legwork yourself if you don't use Rcpp).
| >
| > As 'time_t' is 'long int' on my system, so I cast it to int. The rest is
| > automagic (thanks to RcpP).
| >
| > Notice that I also get today's date down and up correctly.
| >
| > See 'Writing R Extensions' for the details at the C level.
| >
| > See the Rcpp documentation (and, if I may, my book) for details on Rcpp
| if
| > that interests you.
| >
| > Dirk
| >
| > --
| > Dirk Eddelbuettel | e...@debian.org | http://dirk.eddelbuettel.com
| >
|
|
|
| --
|
| *Travel | Programming*
| *http://freecnpro.net* <http://freecnpro.net>
|
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|
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|
--
Dirk Eddelbuettel | e...@debian.org | http://dirk.eddelbuettel.com
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