Thanks much Jim.

On Fri, Dec 5, 2008 at 2:05 PM, jim holtman <jholtman@gmail.com> wrote:

> This should get you close:
>
> > x <- read.table(textConnection("myID myType myNum1 myNum2 myNum3
> + a       Single       10          11           12
> + b       Single       15          25           35
> + c       Double      22          33           44
> + d       Double        4           6             8"), header=TRUE)
> > closeAllConnections()
> > y <- lapply(split(x, x$myType), function(.type){
> +     .means <- colMeans(.type[,3:5])
> +     # create the new line for the data frame
> +     .df <- data.frame(myID='', myType=.type$myType[1], myNum1=.means[1],
> +         myNum2=.means[2], myNum3=.means[3])
> +     rbind(.type, .df) # append the line to the original dataframe
> + })
> > do.call(rbind, y)  # you can add the names your want
>               myID myType myNum1 myNum2 myNum3
> Double.3         c Double   22.0   33.0   44.0
> Double.4         d Double    4.0    6.0    8.0
> Double.myNum1      Double   13.0   19.5   26.0
> Single.1         a Single   10.0   11.0   12.0
> Single.2         b Single   15.0   25.0   35.0
> Single.myNum1      Single   12.5   18.0   23.5
>
>
> On Fri, Dec 5, 2008 at 3:21 PM, Ferry <fmi.mlist@gmail.com> wrote:
> > Dear R users,
> >
> > Suppose I have the following data.frame:
> >
> > myID myType myNum1 myNum2 myNum3
> > a       Single       10          11           12
> > b       Single       15          25           35
> > c       Double      22          33           44
> > d       Double        4           6             8
> >
> > and I want to have new records:
> >
> > myID myType myNum1 myNum2 myNum3
> > e      Single       12.5       18           23.5
> > f       Double      13          19.5         28
> >
> > where record e got its myNum1-3 as the average from record a and b, and
> > record f got its myNum1-3 as the average from record c and d.
> >
> > and the final data.frame should be like the following:
> >
> > myID myType myNum1 myNum2 myNum3
> > a       Single       10          11           12
> > b       Single       15          25           35
> > e       Single       12.5       18           43.5
> > c       Double      22          33           44
> > d       Double        4           6             8
> > f        Double      13          19.5         28
> >
> > Any idea is appreciated. Thanks beforehand.
> >
> > Ferry
> >
> >        [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > 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.
> >
>
>
>
> --
> Jim Holtman
> Cincinnati, OH
> +1 513 646 9390
>
> What is the problem that you are trying to solve?
>

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