On 03/18/2010 04:05 PM, duncandonutz wrote:
I know one of R's advantages is it's ability to index, eliminating the need
for control loops to select relevant data, so I thought this problem would
be easy. I can't crack it. I have looked through past postings, but
nothing seems to match this problem
I have a data set with one column of actors and one column of acts. I need
a list that will give me a pair of actors in each row, provided they both
participated in the act.
Example:
The Data looks like this:
Jim A
Bob A
Bob C
Larry D
Alice C
Tom F
Tom D
Tom A
Alice B
Nancy B
I would like this:
Jim Bob
Jim Tom
Bob Alice
Larry Tom
Alice Nancy
The order doesn't matter (Jim-Bob vs. Bob-Jim), but each pairing should be
counted only once.
Hi duncandonutz,
Try this:
actnames<-read.table("junkfunc/names.dat",stringsAsFactors=FALSE)
actorpairs<-NULL
for(act in unique(actnames$V2)) {
actors<-actnames$V1[actnames$V2 == act]
nactors<-length(actors)
if(nactors > 1) {
indices<-combn(nactors,2)
for(i in 1:dim(indices)[2])
actorpairs<-
rbind(actorpairs,c(actors[indices[1,i]],actors[indices[2,i]]))
}
}
actorpairs
Jim
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