Στις Σαβ 06 Οκτ 2012, ο/η Dirk Eddelbuettel έγραψε: > | Shouldn't there be a special value (like R_NaInt) or a special object or > | something, that represents NA dates?? > > Maybe. Feel like working on a patch? src/RcppDate.cpp is pretty > straightforward and mostly free of template magic. It may just need a > layer of NA testing I didn't add when I wrote that. > > I am with you as R can do this: > > R> as.Date(c(1,2,NA,777)) > [1] "1970-01-02" "1970-01-03" NA "1972-02-17" > R> > > maybe Rcpp should too. But you're the one with the itch to scratch... so > help would be appreciated. > > Dirk
I would LOVE to offer assistance, but I don't think I can do much - my C/C++ knowledge is fairly limited. I checked out Rcpp's src/Date.cpp . It seems all the work is done on Date::update_tm(), which calls gmtime_(). But where is struct tm and time_t defined? I guess this is the internal representation of dates in R, correct? I tried peeking inside a (gunzipped) .RData file to find out how NA is stored. It seems that both with numeric vectors and with date vectors it is stored with the same 8 bytes: 7F F8 00 00 00 00 07 A2, which I believe is the value if R_NaReal. I don't know if that helps, but I guess that struct tm probably contains a double rather than an integer, which should be set to this value. So if you would please give me some hints, I would do my best to help. Theodore _______________________________________________ Rcpp-devel mailing list [email protected] https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
