On Wed, 14 Jul 2010, Meissner, Tony (DFW) wrote:
I have a dataframe that contains time values in the form of
yyyy-mm-dd hh:mm i.e. 2010-07-14 13:00. When I convert this to
numeric via tvec <- as.numeric(Time) I get a number that is in
seconds. So far so good. When I then divide the numeric value by
the number of seconds in a day eg tvec/(60*60*24) I only get integer
values and not fraction of a day which is what I want.
You need to show us a reproducible example (as the posting guide
asked). Clearly
Time <- "2010-07-14 13:00"
as.numeric(Time)
fails to give anything useful, so your description is not correct.
OTOH,
as.numeric(as.POSIXct(Time))/(60*60*24)
[1] 14804.5
does give fractional days.
What do you actually want? Note that not all days are 24 hours long
in most timezones, so if you are doing this to get the time of day you
need to be aware that you get it in UTC (which is why 13:00 is half a
in my timezone is halfway through a day).
What do I need to do to get decimal days?
Tsch??
Tony Meissner
Principal Scientist (Monitoring)
Resources Monitoring Group
Science, Monitoring and Information Division
Department for Water
"Imagine" ?
*(ph) (08) 8595 2209
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DX 51103
Is that in some unstated country? You wrote to a worldwide audience.
--
Brian D. Ripley, rip...@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
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