Yea I thought that would be the story behind it. Thanks. > Date: Sun, 17 Feb 2008 16:15:27 -0500 > From: [EMAIL PROTECTED] > To: [EMAIL PROTECTED] > Subject: Re: [Rd] Arithmetic bug? (found when use POSIXct) (PR#10776) > CC: [EMAIL PROTECTED] > > OK. Good point. > > Note that that article was written 4 years ago > when R was at version 1.9 and POSIXt did not fully support > subseconds. At that time, POSIXct could represent subseconds > internally but it was not used as POSIXlt did not yet support it > and that and the associated digits.sec option did not come until > R version 2.3, released two years after the article was written. > > Try setting the digits.secs option before you run the command > like this: > > > options(digits.secs = 3) > > dp <- Sys.time() > > dp-as.POSIXct(format(dp,tz="GMT")) > Time difference of -5 hours > > On Feb 17, 2008 3:50 PM, <[EMAIL PROTECTED]> wrote: > > > > Hi Gabo, > > > > FAQ 7.31 does not apply to this. "numeric" in R is 64bit which is large eno= > > ugh to handle this. > > > > I > > figured out the cause is that Sys.time() gives millisecond value while > > b<-as.POSIXct(format(a,tz=3D"GMT")) cuts off that part.=20 > > > > Then of course a-b is not 5 hours! > > > > Do it again with "options(digits=3D22)" and you will see what actually happ= > > ened there. > > > > The recommended code from R News is not aware the truth that POSIXlt can re= > > present sub-second time. > > > > Cheers, > > > > B > > _________________________________________________________________ > > Helping your favorite cause is as easy as instant messaging.=A0You IM, we g= > > ive. > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-devel@r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-devel > >
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