I have times and would like to round down to the earliest 30 minute increment. For instance, a time of 2011-04-28 09:02:00 (the as.numeric value = 1303999320) I would like it to be rounded down to: 2011-04-28 09:00:00 (the as.numeric value = 1303999200) Any ideas of how to do this? ----- In theory, practice and theory are the same. In practice, they are not - Albert Einstein -- View this message in context: http://r.789695.n4.nabble.com/Round-down-to-earliest-hour-or-half-hour-tp3509374p3509374.html Sent from the R help mailing list archive at Nabble.com.
I would use package chron and trunc()....
One example from the help of trunc.times (modified):
lirary(chron)
tt <- times(c("12:13:14", "15:46:17"))
trunc(tt, times("00:30:00"))
HTH
Jannis
--- Schatzi <adele_thompson at cargill.com> schrieb am Mo, 9.5.2011:
> Von: Schatzi <adele_thompson at cargill.com>
> Betreff: [R] Round down to earliest hour or half hour
> An: r-help at r-project.org
> Datum: Montag, 9. Mai, 2011 14:06 Uhr
> I have times and would like to round
> down to the earliest 30 minute
> increment. For instance, a time of
> 2011-04-28 09:02:00
> (the as.numeric value = 1303999320)
> I would like it to be rounded down to:
> 2011-04-28 09:00:00
> (the as.numeric value = 1303999200)
>
> Any ideas of how to do this?
>
> -----
> In theory, practice and theory are the same. In practice,
> they are not - Albert Einstein
> --
> View this message in context:
http://r.789695.n4.nabble.com/Round-down-to-earliest-hour-or-half-hour-tp3509374p3509374.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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.
>
One way, assuming your timestamps are POSIXct format:
truncInterval <- function ( x, dx=as.difftime(1,units="days") ) {
xn <- as.numeric( x )
result <- xn - xn %% as.numeric( dx, units="secs" )
class( result ) <- 'POSIXct'
result
}
truncInterval( as.POSIXct(c("2011-04-28 09:20:00", "2011-04-28
09:40:00")), as.difftime(30,units="mins") )
This may not work well if the timestamp granularity is more fine than one
second.
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Schatzi <adele_thompson@cargill.com> wrote:
I have times and would like to round down to the earliest 30 minute increment.
For instance, a time of 2011-04-28 09:02:00 (the as.numeric value = 1303999320)
I would like it to be rounded down to: 2011-04-28 09:00:00 (the as.numeric value
= 1303999200) Any ideas of how to do this? ----- In theory, practice and theory
are the same. In practice, they are not - Albert Einstein -- View this message
in context:
http://r.789695.n4.nabble.com/Round-down-to-earliest-hour-or-half-hour-tp3509374p3509374.html
Sent from the R help mailing list archive at
Nabble.com._____________________________________________
R-help@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.
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