[R] return unique values from date/time class object

[McClatchie, Sam (PIRSA-SARDI)]

Background:
OS: Linux Mandrake 10.1
release: R 2.0.0
editor: GNU Emacs 21.3.2
front-end: ESS 5.2.3
---------------------------------
Colleagues

I have a  wind speed time series with a normal frequency distribution and a
spike in the 5 metres/second bin. The most likely explanation is that the
instrument was returning duplicate values at this speed. To check  this, I
want to extract all the unique times from the series. However, unique()
works with vectors and the object is POSIXt class. I've looked for a similar
function to unique() that will work with this class, but have failed to find
one.

Any suggestions?

Thanks

Sam
----
Sam McClatchie,
Biological oceanography 
South Australian Aquatic Sciences Centre
PO Box 120, Henley Beach 5022
Adelaide, South Australia
email <mcclatchie.sam at saugov.sa.gov.au>
Cellular: 0431 304 497 
Telephone: (61-8) 8207 5448
FAX: (61-8) 8207 5481
Research home page <http://www.members.iinet.net.au/~s.mcclatchie/>
  
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