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Re: DeleteCases

• To: mathgroup at smc.vnet.net
• Subject: [mg98187] Re: [mg98144] DeleteCases
• From: DrMajorBob <btreat1 at austin.rr.com>
• Date: Wed, 1 Apr 2009 05:59:49 -0500 (EST)
• References: <200903310919.EAA03943@smc.vnet.net>
• Reply-to: drmajorbob at bigfoot.com

seq = {{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}};
same[{a_, a_, b_, b_}, {b_, b_, a_, a_}] = True;
same[__] = False;
Union[seq, SameTest -> same]

or

Tally[seq, same][[All, 1]]

Bobby

On Tue, 31 Mar 2009 04:19:23 -0500, Filippo Miatto  
<sottosupremo at gmail.com> 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
>



-- 
DrMajorBob at bigfoot.com

• Follow-Ups:
  • Re: Re: DeleteCases
    • From: Filippo Miatto <miatto@gmail.com>