Does 'unlist' do it for you: > w <- c(3,3,2,1) # vector of weights > q <- 4 # theshold > > # computes which coordinate of w is decisive in each permutation > res <- unlist(sapply( permn(w), function(x) which(w == x[min(which(cumsum(x) > >=q))]) )) > > # complies the frequencies > prop.table( tabulate( res )) [1] 0.4 0.4 0.1 0.1 >
On Tue, Aug 11, 2009 at 7:03 AM, Serguei Kaniovski<serguei.kaniov...@wifo.ac.at> wrote: > Hello! > I have the following combinatorial problem. > Consider the cumulative sums of all permutations of a given weight vector > 'w'. I need to know how often weight in a certain position brings the > cumulative sums equal or above the given threshold 'q'. In other words, > how often each weight is decisive in raising the cumulative sum above 'q'? > > Here is what I do: > > w <- c(3,2,1) # vector of weights > q <- 4 # theshold > > # computes which coordinate of w is decisive in each permutation > res <- sapply( permn(w), function(x) which(w == x[min(which(cumsum(x) >= > q))]) ) > > # complies the frequencies > prop.table( tabulate( res )) > > > The problem I have is that when the weights are not unique, the which() > function returns a list as opposed to a vector. I don’t know how to > proceed when this happens, as tabulate does not work on lists. > > The answer, of course, should be that equal weights are “decisive” equally > often. > > > Can you help? > Thanks a lot! > > Serguei Kaniovski > > ______________________________________________ > 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ 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.
