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
date format
3 messages · alessandro carletti, Brian Ripley, Dimitris Rizopoulos
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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