From edd at debian.org  Sun Mar 15 18:04:22 2009
From: edd at debian.org (Dirk Eddelbuettel)
Date: Sun, 15 Mar 2009 12:04:22 -0500
Subject: [Rd] Conversion and rounding of POSIXct
In-Reply-To: <8b356f880903150928j15ef1d24tba7ae84e409deafa@mail.gmail.com>
References: <8b356f880903150928j15ef1d24tba7ae84e409deafa@mail.gmail.com>
Message-ID: <18877.13590.70146.994092@ron.nulle.part>


Stavros,

Two really quick comments:

a) you need to enable sub-second print formats
b) AFAIK pre-epoch times are second-class citizens

R> options("digits.secs"=6)   ## print with 6 digits for microseconds
R> t0 <- as.POSIXct('1974-01-05 23:59:59.00001')
R> t0
[1] "1974-01-05 23:59:59.00001 CST"
R> as.POSIXlt(t0)
[1] "1974-01-05 23:59:59.00001 CST"
R> as.POSIXct(as.POSIXlt(t0)) - t0
Time difference of 0 secs

All that said, POSIXt is still under-documented and rather mysterious so I
won't / can't comment on all aspects of your post but the above should shed
some light on the first few items.

Hth, Dirk

-- 
Three out of two people have difficulties with fractions.



[Rd] Conversion and rounding of POSIXct
Dirk Eddelbuettel