Re: All permutations of a sequence

*To*: mathgroup at smc.vnet.net*Subject*: [mg76233] Re: All permutations of a sequence*From*: "digrpat" <digrpat at aol.com>*Date*: Fri, 18 May 2007 06:11:50 -0400 (EDT)*References*: <f2h8t7$v4$1@smc.vnet.net>

permutationlist = {1, 2, 3, 4, 5, 6,} allpermutations[list_List] := Drop[Permutations[list], -Length[list]!/2] allpermutations[permutationlist] "Virgil Stokes" <vs at it.uu.se> wrote in message news:f2h8t7$v4$1 at smc.vnet.net... >I would like to get all unique permutations of a sequence (e.g. > {1,2,3,4,5,6,7,8,9,10,11,12,13}) with the constraint that all sequences > that have an opposite ordering are not included (e.g. {13, 12, > 11,10,9,8,6,5,4,3,2,1}) would not be included. > > Are there some Mathematica commands that can be used to efficiently > generate these permutations? > > --V. Stokes > > Posted Via Usenet.com Premium Usenet Newsgroup Services ---------------------------------------------------------- ** SPEED ** RETENTION ** COMPLETION ** ANONYMITY ** ---------------------------------------------------------- http://www.usenet.com