FAQ 7.31 In floating point, you get about 15 digits of precision. If you look at the value of time for today you will see:
1343668783 If you add 5 more digits after the decimal point, you will see that there is not resolution to a microsecond level. I usually assume that I can get millisecond resolution from POSIXct values. On Mon, Jul 30, 2012 at 12:52 PM, Janko Thyson <janko.thyson.rst...@googlemail.com> wrote: > Dear list, > > I'm a bit puzzled by an ambiguity with respect to the representation of > micro-/milliseconds when using 'POSIXlt' objects. > > It seems that the last digit of the 'sec' attribute sometimes seems to > differ from the digits shown when printing the 'POSIXlt' object. You'll > find a little SO post with some example code here: > http://stackoverflow.com/questions/11725517/ambiguity-with-posixlt-representation-when-microseconds-are-included. > > In case you don't want to have a look at that, here's another short example: > > |opts<- options(digits.secs=6) > x<- "2012-07-30 12:10:09.123123" > > posix<- as.POSIXlt(x, tz="Europe/Berlin") > >> posix > [1] "2012-07-30 12:10:09.123122 Europe/Berlin" > >> posix$sec > [1] 9.123123 > | > > # Manually changing the 'sec' attribute > > |posix$sec<- 9.123122 >> posix > [1] "2012-07-30 12:10:09.123122 Europe/Berlin" > # Still '.123122' > > posix$sec<- 9.123124 >> posix > [1] "2012-07-30 12:10:09.123124 Europe/Berlin" > # Now it's '.123124' in both 'representations' > | > > > Thanks a lot for any clarification on this! > Janko > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. -- Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
