I have a combined date and time. I would like to separate them out into two columns so I can do things such as take the mean by time across all dates.
meas<-runif(435) nTime<-seq(1303975800, 1304757000, 1800) nDateT<-as.POSIXct(nTime, origin="1970-01-01") mat1<-cbind(nDateT,meas) means1<- aggregate(mat1$meas, list(nDateT), mean) This doesn't do anything as each day is different, but if I had just the time, it would take the mean outputing 48 values (for each 30 min). Also, sometimes there are missing meas to a specific time. Is there anyway to copy the previous meas if one is missing? ----- 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/separate-date-and-time-tp3517571p3517571.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.
