On Wed, Jan 28, 2004 at 04:38:37PM -0000, Ted Harding wrote:
On 28-Jan-04 Massimiliano Tripoli wrote:
Hi all,
I have problems with years of dates using "chron" package.
I don't understand why R by this istruction:
dates("01/02/29",out.format="d/m/year")
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 ?
I'm puzzled by the above:
dates("01/02/29",out.format="d/m/year")
dates("01/02/30",out.format="d/m/year")
[1] 02/Jan/1930
so chron apparently acts as though time began at 01/01/1930.
However:
-->
origin.: a vector specifying the date with respect to which Julian
dates are computed. Default is 'c(month = 1, day = 1,
year = 1970)'
(which is the orthodox origin of time according to Unix) and, indeed,
origin(dates("01/02/29",out.format="d/m/year"))
month day year
1 1 1970
So why does Massimiliano's example behave as though the origin
were 01/01/1930?
Best wishes,
Ted.
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Date: 28-Jan-04 Time: 16:38:37
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