round Date object to 10 minutes intervals?
You haven't specified how you want 00:05 rounded (it is neither > nor < 5). But here's one way t2 <- strptime(timeStamp, format="%d.%m.%Y %H:%M") t2$min <- round(t2$min, -1)
format(t2, "%d.%m.%Y %H:%M")
[1] "31.03.2011 09:30" "31.03.2011 09:40" "31.03.2011 10:00" "31.03.2011 10:10" [5] "31.03.2011 10:30" "31.03.2011 10:40" "31.03.2011 10:50" "01.04.2011 00:00" That will round 5 to even. You may need to consider things like t2$min <- 10*floor((t2$min + 5)/10) t2$min <- 10*floor((t2$min + 4)/10)
On Mon, 12 Dec 2011, Katharina May wrote:
Hello *,
I'm trying to round time stamps, consisting of a date and time part, to 10
minutes intervals
The timestamps have the following format: %d.%m.%Y %H:%M
*timeStamp <- c("31.03.2011 09:30", "31.03.2011 09:41", "31.03.2011 10:04",
"31.03.2011 10:10", "31.03.2011 10:28", "31.03.2011 10:35", "31.03.2011
10:49", "31.03.2011 23:59")*
should look like this:
*timeStamp2 <- c("31.03.2011 09:30", "31.03.2011 09:40", "31.03.2011
10:00", "31.03.2011 10:10", "31.03.2011 10:30", "31.03.2011 10:40",
"31.03.2011 10:55", "01.04.2011 00:00")*
I've found this topic on the web:
http://stats.stackexchange.com/questions/5305/how-to-re-sample-an-xts-time-series-in-r
library(xts)
align.time(as.POSIXct(timeStamp, format="%d.%m.%Y %H:%M"), 10 * 60)
which uses the align.time function from the library xts BUT as far as I can
see only supports either all timestamps being either rounded up or down
(not both, depending on the minutes 0-9 being either > or < 5 line the way
I need it)
As I'm really struggling with this topic, any help and hint is awarded
with greatest thankfulness from my side?
Best regards, Katharina
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Brian D. Ripley, ripley at 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