Hi,
I'm trying to convert a vector containing dates in
character format ("dd/mm/yy"): mdy.date (from date
package) seems to be able to do that, but it returns
to me a vector containing julian dates... but
negative!
for example:
16/12/03 is converted into -20470
it is because R recognizes year ../03 as 1903, instead
of 2003, but how can I do to solve this problem? (of
course, I could add "36525" to each data, but it's not
very elegant)
Thanks
You haven't even begun to tell us how you are doing this. R does not itself convert dates to numbers, to wit:> as.Date("16/12/03", "%d/%m/%y")[1] "2003-12-16" Here's one way: x <- as.Date("16/12/03", "%d/%m/%y") xx <- as.POSIXlt(x) xx$year <- xx$year-100 as.Date(xx) On Wed, 27 Apr 2005, alessandro carletti wrote:> Hi, > I'm trying to convert a vector containing dates in > character format ("dd/mm/yy"): mdy.date (from date > package) seems to be able to do that, but it returns > to me a vector containing julian dates... but > negative! > for example: > > 16/12/03 is converted into -20470 > > it is because R recognizes year ../03 as 1903, instead > of 2003, but how can I do to solve this problem? (of > course, I could add "36525" to each data, but it's not > very elegant)Not to say wrong. -- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595
you could use "as.Date()", i.e.,
ss <- "16/12/03"
as.Date(ss, "%d/%m/%y")
julian(as.Date(ss, "%d/%m/%y"))
I hope it helps.
Best,
Dimitris
----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven
Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/16/336899
Fax: +32/16/337015
Web: http://www.med.kuleuven.ac.be/biostat/
http://www.student.kuleuven.ac.be/~m0390867/dimitris.htm
----- Original Message -----
From: "alessandro carletti" <alxmilton at yahoo.it>
To: <r-help at stat.math.ethz.ch>
Sent: Wednesday, April 27, 2005 3:08 PM
Subject: [R] date format
> Hi,
> I'm trying to convert a vector containing dates in
> character format ("dd/mm/yy"): mdy.date (from date
> package) seems to be able to do that, but it returns
> to me a vector containing julian dates... but
> negative!
> for example:
>
> 16/12/03 is converted into -20470
>
> it is because R recognizes year ../03 as 1903, instead
> of 2003, but how can I do to solve this problem? (of
> course, I could add "36525" to each data, but it's not
> very elegant)
>
> Thanks
>
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