Remove duplicate elements in lists via recursive indexing
Dear Janko,
I think requires a for loop. The approach I took here was mark the dups, then dump them all in one hit:
testData = expand.grid(letters[1:4],c(1:3))
testData$keep=F
uniqueIDS = unique(testData$Var1)
for(thisID in uniqueIDS) {
firstCaseOnly = match(thisID,testData$Var1)
testData[firstCaseOnly,"keep"]=T
}
(testData = testData[testData$keep==T,])
On 23 May 2011, at 11:59 AM, Janko Thyson wrote:
Dear list,
I'm trying to solve something pretty basic here, but I can't really come up with a good solution. Basically, I would just like to remove duplicated named elements in lists via a their respective recursive indexes (given that I have a routine that identifies these recursive indexes). Here's a little example:
# VECTORS
# Here, it's pretty simple to remove duplicated entries
y <- c(1,2,3,1,1)
idx.dupl <- which(duplicated(y))
y <- y[-idx.dupl]
# /
# LISTS
x <- list(a=list(a.1.1=1, a.1.1=2, a.1.1=3))
x[[c(1,1)]]
x[[c(1,2)]] # Should be removed.
x[[c(1,3)]] # Should be removed.
# Let's say a 'checkDuplicates' routine would give me:
idx.dupl <- list(c(1,2), c(1,3))
# Remove first duplicate:
x[[idx.dupl[[1]]]] <- NULL
x
# Problem:
# Once I remove the first duplicate, my duplicate index would have to be
# updated as well as there is not third element anymore.
x[[idx.dupl[[2]]]] <- NULL
# So something like this would not work:
sapply(idx.dupl, function(x.idx){
x[[x.idx]] <<- NULL
})
# /
Sorry if I'm missing something totally obvious here, but do you have any idea how to solve this?
Thanks a lot,
Janko
______________________________________________ R-help at 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.