Here is one way of doing it: > time<-c("2000-10-03 14:00:00","2000-10-03 14:10:00","2000-10-03 14:20:00", + "2000-10-03 15:30:00","2000-10-03 16:40:00","2000-10-03 16:50:00", + "2000-10-03 17:00:00","2000-10-03 17:10:00","2000-10-03 17:20:00", + "2000-10-03 18:30:00","2000-10-04 14:00:00","2000-10-04 14:10:00", + "2000-10-04 14:20:00","2000-10-04 15:30:00","2000-10-04 16:40:00", + "2000-10-04 16:50:00","2000-10-04 17:00:00","2000-10-04 18:30:00", + "2000-10-04 18:30:00","2000-10-04 18:30:00") > # remark the last date is occuring 3 times > > precipitation<-c(NA,0.1,0,0,NA,0,0.2,0.3,0.5,6,7,8,9,1,0,0,NA,0,1,0) > > my.df <- data.frame(time=as.POSIXct(time), precip=precipitation) > # get only good data > my.df <- my.df[complete.cases(my.df),] > tapply(my.df$precip, as.POSIXct(trunc(my.df$time, 'day')), sum) 2000-10-03 2000-10-04 7.1 26.0 >
On 5/29/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > Dear all, > > I am trying to execute the following example: > > time<-c("2000-10-03 14:00:00","2000-10-03 14:10:00","2000-10-03 > 14:20:00","2000-10-03 15:30:00","2000-10-03 16:40:00","2000-10-03 > 16:50:00","2000-10-03 17:00:00","2000-10-03 17:10:00","2000-10-03 > 17:20:00","2000-10-03 18:30:00","2000-10-04 14:00:00","2000-10-04 > 14:10:00","2000-10-04 14:20:00","2000-10-04 15:30:00","2000-10-04 > 16:40:00","2000-10-04 16:50:00","2000-10-04 17:00:00","2000-10-04 > 18:30:00","2000-10-04 18:30:00","2000-10-04 18:30:00") > # remark the last date is occuring 3 times > > precipitation<-c(NA,0.1,0,0,NA,0,0.2,0.3,0.5,6,7,8,9,1,0,0,NA,0,1,0) > > library(zoo) > > z <- zoo(precipitation, as.POSIXct(time, tz = "GMT")) > Warning message: > some methods for "zoo" objects do not work if the index entries in > 'order.by' are not unique in: zoo(precipitation, as.POSIXct(time, tz = > "GMT")) > > # then I want to do the sum per hour > > z_sum_per_hour <- aggregate(na.omit(z), function(x) as.POSIXct(trunc(x, > "hour")),sum) > Warning message: > some methods for "zoo" objects do not work if the index entries in > 'order.by' are not unique in: zoo(rval[i], x.index[i]) > > > > Do anyone has an idea how to avoid that ? > > > > Thanks in advance > > > Jessica > > ______________________________________________ > R-help@stat.math.ethz.ch 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? [[alternative HTML version deleted]] ______________________________________________ R-help@stat.math.ethz.ch 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.