Re: DeleteCases

*To*: mathgroup at smc.vnet.net*Subject*: [mg98155] Re: DeleteCases*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Wed, 1 Apr 2009 05:53:46 -0500 (EST)*Organization*: Uni Leipzig*References*: <gqsn69$3qp$1@smc.vnet.net>*Reply-to*: kuska at informatik.uni-leipzig.de

Hi, lst = {{0, 0, 1, 1}, {0, 0, 2, 2}, {0, 0, 3, 3}, {1, 1, 0, 0}, {1, 1, 2, 2}, {1, 1, 3, 3}, {2, 2, 0, 0}, {2, 2, 1, 1}, {2, 2, 3, 3}, {3, 3, 0, 0}, {3, 3, 1, 1}, {3, 3, 2, 2}}; and Cases[ Flatten[Outer[List, lst, lst, 1], 1], {{a_, a_, b_, b_}, {b_, b_, a_, a_}}] ? Regards Jens Filippo Miatto wrote: > Dear all, > Given this example list: > > {{0, 0, 1, 1}, {0, 0, 2, 2}, {0, 0, 3, 3}, {1, 1, 0, 0}, {1, 1, 2, 2}, > {1, 1, 3, 3}, {2, 2, 0, 0}, {2, 2, 1, 1}, {2, 2, 3, 3}, {3, 3, 0, 0}, > {3, 3, 1, 1}, {3, 3, 2, 2}} > > I need the elements {a,a,b,b} and {b,b,a,a} to be the same, i.e. i > want to delete one of the two occurrences from the list. (or all but > one if the condition is more complicated, say {a,b,c,d} and {b,a,c,d} > or {a,b,c,d} and {a,b,d,c}) > How can i do that? Can i use DeleteCases? if so, what conditional > should I use to compare different elements in the list? > I tried without success for all the night.. (it's 6.15AM now!) > Thank you, > > Filippo >