Thanks for the help. A workaround seems indeed easy to write, for
example, by rounding the the value of 'm' inside
chron:::julian.default(), or only passing integers to the function.
I never intended to use a case involving a quadrillionth of a day, but
encountered the problem when converting a dates in YYYY.MM format to a
CHRON object. Here is an example for future reference (the output might
be highly system-dependent):
> library(chron)
> date <- 2012.02
> y <- floor(date)
> m <- (date %% 1) * 100
> julian(2, 1, 2012) - julian(m, 1, y)
[1] 1
~Andreas
P.S.: I have included Kurt Hornik on the email.
On 3/23/2012 10:52 PM, R. Michael Weylandt wrote:
julian() is in the package base. chron only provides julian.default to
avoid the error Uwe observed. If you look at the code for
julian.default, it's not too hard to see why date will be slightly
more sensitive to "numeric fuzz"....whether that's intentional (or
even a good/bad thing) is somewhat hard to say, but I'd guess the
maintainer didn't really consider a use case involving one
quadrillionth of a day.
Is it problematic for you? If so, a workaround is not hard to provide
Michael
On Fri, Mar 23, 2012 at 4:17 PM, Andreas Eckner<andr...@eckner.com> wrote:
Sorry, forgot to mention: R version 2.14.2
The function julian() is part of the "chron" package of the base
distribution.
On 3/23/2012 2:47 PM, Uwe Ligges wrote:
On 23.03.2012 15:45, Andreas Eckner wrote:
Hi,
does anybody know if the following behavior of julian() is intentional?
julian(2, 1, 2012) - julian(2 - 1e-15, 1, 2012)
[1] 1
julian(2, 1, 2012) - julian(2, 1 - 1e-15, 2012)
[1] 0
julian(2, 1, 2012) - julian(2, 1, 2012 - 1e-15)
[1] 0
In other words, julian() is subject to numerical noise in the 'day'
argument, but not in the 'month' and 'year' argument? Another example:
julian(2 - 1e-15, 1, 2012) - julian(1 - 1e-15, 1, 2012)
[1] 30
Which vbersion of R are you talking about?
I get:
julian(2, 1, 2012) - julian(2 - 1e-15, 1, 2012)
Error in UseMethod("julian") :
no applicable method for 'julian' applied to an object of class
"c('double', 'numeric')"
Uwe Ligges
Thanks,
Andreas
______________________________________________
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.
______________________________________________
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.
______________________________________________
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.
