[R] mean of a value of the last 2 hours

[Rui Barradas]

Hello,

Or


ct <- cut(myframe2$myframestime, breaks = "2 hour")
ave(myframe2$Hunger, ct)

And assign the output of 'ave' to a new column.

Hope this helps,

Rui Barradas
Em 25-10-2012 15:50, arun escreveu:
> Hi,
> May be this helps:
>   new1<-with(myframe2,aggregate(cbind(Hunger,myframestime),by=list(ID=ID), function(x) mean(tail(x,2))))[,1:2]
>   merge(myframe2,new1,by="ID",all=TRUE)
> #     ID Hunger.x        myframestime Hunger.y
> #1  Bert        2 2012-09-24 09:00:00      1.5
> #2  Bert        2 2012-09-24 10:00:00      1.5
> #3  Bert        1 2012-09-24 11:00:00      1.5
> #4 Ernie        1 2012-09-24 09:00:00      1.0
> #5 Ernie        1 2012-09-24 10:00:00      1.0
> #6 Ernie        1 2012-09-24 11:00:00      1.0
> A.K.
>
>
>
>
> ----- Original Message -----
> From: Tagmarie <Ramgad82 at gmx.net>
> To: r-help at r-project.org
> Cc:
> Sent: Thursday, October 25, 2012 10:35 AM
> Subject: [R] mean of a value of the last 2 hours
>
> Hello,
> I have a data frame somewhat like that:
>
> myframe <- data.frame (ID=c("Ernie", "Ernie", "Ernie", "Bert", "Bert",
> "Bert"), Timestamp=c("24.09.2012 09:00", "24.09.2012 10:00", "24.09.2012
> 11:00"), Hunger=c(1,1,1,2,2,1) )
> myframestime <- as.POSIXct (strptime(as.character(myframe$Timestamp),
> "%d.%m.%Y %H:%M"), tz="GMT")
> myframe2 <- cbind (myframe,myframestime)
> myframe2$Timestamp <- NULL
> myframe2
>
> I want to add an additional column at the right and get in each row a value
> which shows the mean of "hunger" of the last two hours.
>
> Does anyone know how that works? That would be very helpful.
>
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/mean-of-a-value-of-the-last-2-hours-tp4647415.html
> Sent from the R help mailing list archive at Nabble.com.
>
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>
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.