R help - Jul 2011 - Odd behaviour of as.POSIXct

Dear all,

how come the first loop in the below fails, but the second performs as
expected?

days <- as.Date( c("2000-01-01", "2000-01-02") )

for(day in days)
{
    as.POSIXct(day)
}

for( n in 1:length(days) )
{
    show(as.POSIXct(days[n]))
}

Many thanks, Jo

	[[alternative HTML version deleted]]

day doesn't exist?
That would be the 1st problem.



Johannes Egner wrote:
> 
> Dear all,
> 
> how come the first loop in the below fails, but the second performs as
> expected?
> 
> days <- as.Date( c("2000-01-01", "2000-01-02") )
> 
> for(day in days)
> {
>     as.POSIXct(day)
> }
> 
> for( n in 1:length(days) )
> {
>     show(as.POSIXct(days[n]))
> }
> 
> Many thanks, Jo
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org 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.
> 
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On 15/07/2011 12:15 PM, Johannes Egner wrote:
> Dear all,
>
> how come the first loop in the below fails, but the second performs as
> expected?
>
> days<- as.Date( c("2000-01-01", "2000-01-02") )
>
> for(day in days)
> {
>      as.POSIXct(day)
> }
"day" in the loop above is an integer without a class, it's not a
Date.
If you did

for (day in days) {
   class(day) <- class(days)
   print(as.POSIXct(day))
}

you won't get an error.  (I don't know if you'll be happy with what
you
get; the time zone is an issue.)

Duncan Murdoch
> for( n in 1:length(days) )
> {
>      show(as.POSIXct(days[n]))
> }
>
> Many thanks, Jo
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org 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.