Re: Keeping order with Union
- To: mathgroup at smc.vnet.net
- Subject: [mg32606] Re: [mg32590] Keeping order with Union
- From: Mianlai Zhou <lailai at nikhef.nl>
- Date: Thu, 31 Jan 2002 01:45:33 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Hi, Dave, this is easy. Just use:
MyUnion := (# //. {a___, b_, c___, b_, d___} :> {a, b, c, d}) &
and MyUnion[{a,b,c,d,d,f,c,e}] will give {a,b,c,d,f,e}, for example.
Good luck!
Mianlai Zhou
Theory Group, NIKHEF
Amsterdam, The Netherlands
On Wed, 30 Jan 2002, Dave Snead wrote:
> I'd like a function that throws out duplicate entries in a list and keeps
> the
> original list order. (when it sees 2 equal entries it throws out the one
> that is later in the list). I'd use Union, but it sometimes changes the
> order of the elements in the list. What's the tersest way to do this?
> Thanks in advance,
> Dave Snead
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