Full_Name: Bo Zhou Version: 2.6.1 (2007-11-26) OS: Windows XP Submission from: (NULL) (207.237.54.242)
Hi, I found an arithmetic problem when I'm doing something with POSIXct The code to reproduce it is as follows (This is the recommended way of finding out time zone difference on R News 2004-1 Page 32 URL http://cran.r-project.org/doc/Rnews/Rnews_2004-1.pdf) a=Sys.time() b<-as.POSIXct(format(a,tz="GMT")) a-b unclass(a) unclass(b) unclass(a)-unclass(b) as.numeric(a) as.numeric(b) as.numeric(a)-as.numeric(b) The result on my machine > a=Sys.time() > b<-as.POSIXct(format(a,tz="GMT")) > a-b Time difference of -4.999969 hours > unclass(a) [1] 1203184447 > unclass(b) [1] 1203202447 attr(,"tzone") [1] "" > unclass(a)-unclass(b) [1] -17999.89 attr(,"tzone") [1] "" > as.numeric(a) [1] 1203184447 > as.numeric(b) [1] 1203202447 > as.numeric(a)-as.numeric(b) [1] -17999.89 > ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
