Thanks! Yes, however, this seems a bit wasteful. Just wondering if there are other, more efficient options possible.
Best wishes, Ranjan On Thu, 29 Mar 2018 22:20:19 -0400 Boris Steipe <boris.ste...@utoronto.ca> wrote: > If one is equal to the reverse of another, keep only one of the pair. > > B. > > > > > On Mar 29, 2018, at 9:48 PM, Ranjan Maitra <mai...@email.com> wrote: > > > > Dear friends, > > > > I would like to get all possible arrangements of n objects listed 1:n on a > > circle. > > > > Now this is easy to do in R. Keep the last spot fixed at n and fill in the > > rest using permuations(n-1, n-1) from the gtools package. > > > > However, what if clockwise or counterclockwise arrangements are the same? I > > know that half of the above (n - 1)! arrangements are redundant. > > > > Is there an easy way to list these (n-1)!/2 arrangements? > > > > I thought of only listing the first half from a call to permuations(n - 1, > > n - 1), but while this holds for n = 4, it does not for n = 5. So, I am > > wondering if there is another function or tweak which would easily do this. > > > > Many thanks in advance for any help. and best wishes, > > Ranjan > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > 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 -- To UNSUBSCRIBE and more, see > 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. > -- Important Notice: This mailbox is ignored: e-mails are set to be deleted on receipt. Please respond to the mailing list if appropriate. For those needing to send personal or professional e-mail, please use appropriate addresses. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.