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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Sent from my phone. Please excuse my brevity.
Schatzi <adele_thomp...@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
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