Here is a solution using doBy and Gabor's DF2 created below: library( doBy ) newrows <- summaryBy ( myNum1 + myNum2 + myNum3 ~ myType , DF2, keep.names = TRUE ) newrows[,"myID"] <- "+" rbind ( DF2, newrows)
----- Original message ----- From: "Gabor Grothendieck" <[EMAIL PROTECTED]> To: "Ferry" <[EMAIL PROTECTED]> Cc: r-help@r-project.org Date: Fri, 5 Dec 2008 17:50:42 -0500 Subject: Re: [R] adding rows as arithmatic calculation on original rows Here is a solution using sqldf library(sqldf) DF2 <- structure(list(myID = structure(1:4, .Label = c("a", "b", "c", "d"), class = "factor"), myType = structure(c(2L, 2L, 1L, 1L), .Label = c("Double", "Single"), class = "factor"), myNum1 = c(10, 15, 22, 4), myNum2 = c(11, 25, 33, 6), myNum3 = c(12, 35, 44, 8)), .Names = c("myID", "myType", "myNum1", "myNum2", "myNum3"), row.names = c(NA, -4L), class = "data.frame") sqldf("select 1 TotalLevel, '+' myID, myType, avg(myNum1) myNum1, avg(myNum2) myNum2, avg(myNum3) myNum3 from DF2 group by myType union select 0 TotalLevel, * from DF2 order by myType, TotalLevel, myID", method = "raw")[-1] The output is (display in fixed font): myID myType myNum1 myNum2 myNum3 1 c Double 22.0 33.0 44.0 2 d Double 4.0 6.0 8.0 3 + Double 13.0 19.5 26.0 4 a Single 10.0 11.0 12.0 5 b Single 15.0 25.0 35.0 6 + 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. > ______________________________________________ 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. ______________________________________________ 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.