Hi, I think I found the solution. Using doBy library, I got:
testDF.result2 <- summaryBy(n1+n2 ~ v1+v2, data = testDF, FUN=sum) > testDF.result2 v1 v2 n1.sum n2.sum 1 a a1 6 66 2 a a2 4 24 3 a a3 5 25 4 b b1 13 53 5 b b2 27 87 6 c c1 11 31 7 c c2 39 99 8 c c3 15 35 9 d d1 16 36 10 d d2 17 37 11 d d3 18 38 12 d d4 39 79 In any case, did I do something wrong using the aggregate function? Thanks, Ferry On Thu, Mar 19, 2009 at 6:09 PM, Ferry <[email protected]> wrote: > Hi, > > I am trying to aggregate the sum of my test data.frame as follow: > > testDF <- data.frame(v1 = c("a", "a", "a", "a", "a", "b", "b", "b", "b", > "b", "c", "c", "c", "c", "c", "d", "d", "d", "d", "d"), > v2 = c("a1", "a1", "a1", "a2", "a3", "b1", "b1", "b2", > "b2", "b2", "c1", "c2", "c2", "c2", "c3", "d1", "d2", "d3", "d4", "d4"), > n1 = 1:20, > n2 = 21:40 ) > > testDF <- orderBy( ~ v1+v2, data = testDF) > rownames(testDF) <- NULL > > > testDF > v1 v2 n1 n2 > 1 a a1 1 21 > 2 a a1 2 22 > 3 a a1 3 23 > 4 a a2 4 24 > 5 a a3 5 25 > 6 b b1 6 26 > 7 b b1 7 27 > 8 b b2 8 28 > 9 b b2 9 29 > 10 b b2 10 30 > 11 c c1 11 31 > 12 c c2 12 32 > 13 c c2 13 33 > 14 c c2 14 34 > 15 c c3 15 35 > 16 d d1 16 36 > 17 d d2 17 37 > 18 d d3 18 38 > 19 d d4 19 39 > 20 d d4 20 40 > > > > testDF.result <- aggregate(list(testDF$n1, testDF$n2), by = list(testDF$v1, > testDF$v2), FUN = sum) > > > testDF.result > Group.1 Group.2 X1.20 X21.40 > 1 a a1 6 66 > 2 a a2 4 24 > 3 a a3 5 25 > 4 b b1 13 53 > 5 b b2 27 87 > 6 c c1 11 31 > 7 c c2 39 99 > 8 c c3 15 35 > 9 d d1 16 36 > 10 d d2 17 37 > 11 d d3 18 38 > 12 d d4 39 79 > > > > > However, when I applied it to my real data, it failed. It seems that > aggregate require more memory that I have currently (I am using WinXP, > R2.8.0, 2GB RAM). > > Basically I want to perform aggregate sum on my numeric fields (in the > above case, n1 and n2) based on condition of v1 and v2. > > Problem is, I have a lot more of than just two numerics and conditioning > fields. > > In SQL, I would do: > select v1, v2, sum(n1), sum(n2) from myData > group by v1, v2; > > Am I using a wrong function / library (or even wrong approach)? If so, can > you suggest which one? > > Any pointer is really appreciated. > > Thanks, > > Ferry > [[alternative HTML version deleted]] ______________________________________________ [email protected] 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.
