Odd behaviour of as.POSIXct

An embedded and charset-unspecified text was scrubbed...
Name: not available
URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20110715/8467bd42/attachment.pl>
day doesn't exist?
That would be the 1st problem.
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.

--
View this message in context: http://r.789695.n4.nabble.com/Odd-behaviour-of-as-POSIXct-tp3670414p3670454.html
Sent from the R help mailing list archive at Nabble.com.
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.
An embedded and charset-unspecified text was scrubbed...
Name: not available
URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20110716/0f61f18f/attachment.pl>
Also, if we make days a list, the class attributes are kept when looping
over the list, ie.

days<- list( as.Date( c("2000-01-01", "2000-01-02") ) )
Do you realise that that's a list with length one?

I suspect you want

days <- as.list( as.Date( c("2000-01-01", "2000-01-02") ) )
for (day in days) {
  print(day)
}

Hadley
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/