Message-ID: <Pine.GSO.4.31.0401281311530.836-100000@toucan.stats>
Date: 2004-01-28T13:15:44Z
From: Brian Ripley
Subject: dates function
In-Reply-To: <006d01c3e589$f220ec30$5a1aa7c0@pc2690>
On Wed, 28 Jan 2004, Massimiliano Tripoli wrote:
> I have problems with years of dates using "chron" package.
> I don't understand why R by this istruction:
It's not R, it is package chron. R has its own date-time functions.
> > dates("01/02/29",out.format="d/m/year")
> [1] 02/Jan/2029
>
> > dates("01/02/30",out.format="d/m/year")
> [1] 02/Jan/1930
>
> reads "29" as 2029
> and "30" as 1930. How could I change to read "00" to "05" like 2000 to 2005 and "06" to "99" like 1906 to 1999 ?
Read the code for convert.dates. You need to set
option("chron.year.expand") to a suitable function, the prototype being
year.expand and it will be easy to achieve what you want.
This answers your message under the misleading subject `Julian dates' too.
--
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 272860 (secr)
Oxford OX1 3TG, UK Fax: +44 1865 272595