On 2010-10-07 12:09, Phil Spector wrote:
Is this what you're looking for?dat = read.table(textConnection('V1 V2 v3+ 1 a 1.3 + 1 a 1.5 + 1 b 2.0 + 1 a 2.3 + 1 a 3.4 + 1 c 5.5 + 1 d 6.0 + 1 a 7.0 + 2 f 1.5 + 2 g 1.6 + 2 f 3.4 + 2 f 4.0 + 2 g 4.6 + 2 c 5.0 + 2 a 5.3'),header=TRUE)aggregate(dat$v3,dat[c('V1','V2')],max)V1 V2 x 1 1 a 7.0 2 2 a 5.3 3 1 b 2.0 4 1 c 5.5 5 2 c 5.0 6 1 d 6.0 7 2 f 4.0 8 2 g 4.6 - Phil Spector Statistical Computing Facility Department of Statistics UC Berkeley spec...@stat.berkeley.edu
Or with plyr: require(plyr) result <- ddply(dat, .(V1,V2), summarize, MAX=max(v3)) -Peter Ehlers
On Thu, 7 Oct 2010, wangguojie2006 wrote:Dear fellows, I've been working this problem for a day and still can't see where the problem is. I really appreciate if anyone can help me out. My data is like: V1 V2 v3 1 a 1.3 1 a 1.5 1 b 2.0 1 a 2.3 1 a 3.4 1 c 5.5 1 d 6.0 1 a 7.0 2 f 1.5 2 g 1.6 2 f 3.4 2 f 4.0 2 g 4.6 2 c 5.0 2 a 5.3 What I want to do is to get the max value of V3 for each unique V2 in each V1. For example, when V1=1, unique V2 is (a, b, c, d), and corresponding max value of V3 is (7.0, 2.0, 5.5, 6.0). And V1=2, unique V2 is (f, g, c, a) and max value of V3 is (4.0, 4.6, 5.0, 5.3). Then combinne these max values. My code is like: z<-NULL x<-NULL;y<-NULL for (j in 1:2) { x<-unique(V2[V1==j]) for (i in 1:length(x)) { y[i]<-max(V3[V2==x[i]& V1==j]) } z<-c(z,y) } length(z) My problem is the length of z is much bigger than the length of I'm supposed to get, like above data, I should only get 8 max values. But the code will return me a number bigger than 8. I'm thinking there might be some overlapping problem. Can someone help? Thank you for your time. Best, -- View this message in context: http://r.789695.n4.nabble.com/Need-help-for-loop-code-thanks-tp2967036p2967036.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
