# [R] Sum per hour

Gabor Grothendieck ggrothendieck at gmail.com
Thu May 24 21:42:10 CEST 2007

There was a missing ) on this one.  Here it is again:

library(chron)
z <- zoo(precipitation, as.chron(as.POSIXct(time, tz = "GMT")))
aggregate(z, function(x) chron(trunc(times(x), "01:00:00")), sum)

On 5/24/07, Gabor Grothendieck <ggrothendieck at gmail.com> wrote:
> We could do it using either POSIXct or chron:
>
> library(zoo)
>
> # POSIXct
> z <- zoo(precipitation, as.POSIXct(time, tz = "GMT"))
> aggregate(z, function(x) as.POSIXct(trunc(x, "hour")), sum)
>
> # chron
> library(chron)
> z <- zoo(precipitation, as.chron(as.POSIXct(time, tz = "GMT"))
> aggregate(z, function(x) chron(trunc(times(x), "01:00:00")), sum)
>
>
> On 5/24/07, jessica.gervais at tudor.lu <jessica.gervais at tudor.lu> wrote:
> >
> > Dear all,
> >
> > I have a list of precipitation record and a list of time
> > I would like to sum them up per hour, or per day.
> > Does such a function exist ?
> >
> >
> > 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
> > 17:10:00","2000-10-04 17:20:00","2000-10-04 18:30:00")
> >
> > precipitation<-c(0,0.1,0,0,0,0,0.2,0.3,0.5,6,7,8,9,1,0,0,0,0,1,0)
> >
> > DATA<-cbind(time,precipitation)
> >
> > ... ?
> > how to sum up per hour ?
> >
> >
> > Jessica
> >
> > ______________________________________________
> > R-help at stat.math.ethz.ch mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help