[R] Extract time only from POSIXlt object

[David Winsemius]

On Jan 29, 2011, at 7:45 PM, Simon Goodman wrote:

>
> How can I extract only the time component from an POSIXlt object?
>
> For example if I try the following it still returns both the date and
> time...
>
>> as.POSIXlt(tr.date[1])
> [1] "2010-10-18 21:46:53"
>> as.POSIXlt(tr.date[1],"%H:%M:%S")
> [1] "2010-10-18 21:46:53"
>
> round and trunc don't help...  is there an "as.Time" equivalent to  
> as.Date
> ?

 > ptime <- as.POSIXlt("2010-10-18 21:46:53")
 > ptime
[1] "2010-10-18 21:46:53"
 > format(ptime, format="%H:%M:%S")
[1] "21:46:53"

This is a character value, no longer a time.
-- 

David Winsemius, MD
West Hartford, CT