Re: [R] Strange julian and/or strptime

From: Kåre Edvardsen <ked_at_nilu.no>
Date: Fri, 23 May 2008 13:17:28 +0200

I'm on an Ubuntu Linux PC, and get the same wrong result as you. I could not work out what the description of '%y' really ment, so I did not realize this was operating system specific in this sense. Anyway, I'll find a way to work around this bug.

Have a nice weekend,
Kare

On Fri, 2008-05-23 at 10:41 +0100, Prof Brian Ripley wrote:

> On my Linux box:
>
> > strptime("010169", format = "%d%m%y")
> [1] "1969-01-01"
> > strptime("311268", format = "%d%m%y")
> [1] "2068-12-31"
>
> >From the help page:
>
> '%y' Year without century (00-99). If you use this on input, which
> century you get is system-specific. So don't! Often values
> up to 69 (or 68) are prefixed by 20 and 70 (or 69) to 99 by
> 19.
>
> If all else fails, read the documentation (but the posting guide asks you
> to do that before posting). Elsewhere on that help page it refers you to
> your OS documentation -- the posting guide asked for your OS 'at a
> minimum', but as you didn't follow it so we have no idea which you used.
>
> On Fri, 23 May 2008, Kåre Edvardsen wrote:
>
> > Hi r-helpers...
> >
> > Why do I get this strange huge jump of 36524 days when changing "origin"
> > from 1969-01-01 to 1968-12-31. It should still be close to zero! This
> > really messes up my calculations of follow-up times in my analyses.
> >
> >> julian(strptime("010169", format = "%d%m%y"),origin =
> > as.Date("1969-01-01"))
> >> Time difference of -0.04166667 days
> >
> >> julian(strptime("311268", format = "%d%m%y"),origin =
> > as.Date("1968-12-31"))
> >> Time difference of 36524.96 days
> >
> >
> > Cheers,
> > Kare
> >
> > [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help_at_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.
> >
>

        [[alternative HTML version deleted]]



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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. Received on Fri 23 May 2008 - 11:20:36 GMT

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