[R] Aggregate records to 10min

[Fankhauser GEP Data Consulting]

Hi Jim,
Thanks a lot! It works now. I didn't remember how to access the 
datetimes in w10min. names(...) is the solution!

Rolf

Jim Lemon wrote:
> Hi Rolf,
> If I get the above, perhaps if you change the names of w10min after 
> applying the calculation:
>
> raindata<-data.frame(value=round(runif(60,0,4),1),
> ptime=paste("2016-01-17 ","15:",0:59,sep=""))
> t10min <- 600*floor(as.integer(as.POSIXct(raindata$ptime))/600)
> w10min <- tapply(raindata$value,t10min,sum)
> names(w10min)<-format(as.POSIXct(as.numeric(names(w10min)),
>  tz="AEST",origin="1970-01-01"),"%m/%d/%Y %H:%M")
>
> Jim
>
>
> On Sun, Jan 17, 2016 at 5:45 AM, Rolf Fankhauser 
> <rolf.fankhauser at gepdata.ch <mailto:rolf.fankhauser at gepdata.ch>> wrote:
>
>     Hi
>
>     I would like to aggregate a rainfall series with 1min records
>     (timestamp and value of 0.1mm from a tipping bucket raingauge) to
>     10min values by summing up the values.
>
>     # ptime is a POSIXlt datetime value with tz="GMT"
>
>     t10min <- 600*floor(as.integer(as.POSIXct(data$ptime))/600)
>     w10min <- tapply(data$value, format(as.POSIXct(t10min, tz="GMT",
>     origin = "1970-01-01"), "%Y-%m-%d %H:%M"), sum)
>     write.table(as.matrix(w10min),"data 10min.txt", row.names=TRUE,
>     col.names=FALSE, quote=FALSE)
>
>     This code works but I would like to have the result in datetime
>     format of %m/%d/%Y %H:%M. When I output this format the records
>     are not chronologically sorted but text-sorted because dimnames of
>     w10min is of type character (because of the format function).
>     Is there an easier way summing up the records to 10min records?
>
>     Thanks,
>     Rolf
>
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>


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