What is the recommended way to convert/coerce and integer to a POSIXct please? d <- as.POSIXct(Sys.Date()) i <- as.integer(d) as.POSIXct(i) Error in as.POSIXct.default(i) : do not know how to convert 'i' to class "POSIXlt" This appears to be the behaviour in 2.3.1 and 2.4.0 on windows XP. I have tried searching on this and found as.Date.integer in package zoo which performs a similar function but wondered if there was something basic I was missing in the base distribution? cheers
Here are a few ways:
now <- Sys.time()
Epoch <- now - as.numeric(now)
i + Epoch
structure(i, class = c("POSIXt", "POSIXct"))
class(i) <- c("POSIXt", "POSIXct")
On 10/4/06, paul sorenson <news01 at metrak.com>
wrote:> What is the recommended way to convert/coerce and integer to a POSIXct
> please?
>
> d <- as.POSIXct(Sys.Date())
> i <- as.integer(d)
>
> as.POSIXct(i)
> Error in as.POSIXct.default(i) : do not know how to convert 'i' to
class
> "POSIXlt"
>
> This appears to be the behaviour in 2.3.1 and 2.4.0 on windows XP.
>
> I have tried searching on this and found as.Date.integer in package zoo
> which performs a similar function but wondered if there was something
> basic I was missing in the base distribution?
>
> cheers
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
On Wed, 4 Oct 2006, paul sorenson wrote:> What is the recommended way to convert/coerce and integer to a POSIXct > please? > > d <- as.POSIXct(Sys.Date()) > i <- as.integer(d) > > as.POSIXct(i) > Error in as.POSIXct.default(i) : do not know how to convert 'i' to class > "POSIXlt" > > This appears to be the behaviour in 2.3.1 and 2.4.0 on windows XP. > > I have tried searching on this and found as.Date.integer in package zoo > which performs a similar function but wondered if there was something > basic I was missing in the base distribution?It's documented on the help page for as.POSIXct in 2.4.0. What that integer means is undefined unless you also tell R the time origin. -- 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