Re: Complement
- To: mathgroup at smc.vnet.net
- Subject: [mg6102] Re: [mg6100] Complement
- From: Allan Hayes <hay at haystack.demon.co.uk>
- Date: Fri, 21 Feb 1997 23:46:06 -0500
- Sender: owner-wri-mathgroup at wolfram.com
Houshou Chen <houshou at eecs.umich.edu>
[mg6100] Complement
writes
> The result of Complement always resort the order, Is there any code
> such that taking the complement without changing the original
> order?
>
> Complement[{5,4,3,2,1},{1,2}] is {3, 4, 5}, I would like the result
> to be {5,4,3} instead.
Houshou:
DeleteCases[{5,4,3,2,1}, Alternatives@@{1,2}]
{5, 4, 3}
Because Alternatives@@{1,2} becomes Alternatives[1,2] we can work
with lists as inputs.
Allan Hayes
hay at haystack.demon.co.uk
http://www.haystack.demon.co.uk