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 <[EMAIL PROTECTED]> 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?
______________________________________________
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.
