Re: Generalizing Complement to handle multiple occurrences of elements
- To: mathgroup at smc.vnet.net
- Subject: [mg112456] Re: Generalizing Complement to handle multiple occurrences of elements
- From: Helen Read <hpr at together.net>
- Date: Thu, 16 Sep 2010 05:59:19 -0400 (EDT)
- References: <i6q0ml$l7c$1@smc.vnet.net>
- Reply-to: read at cems.uvm.edu
On 9/15/2010 4:38 AM, Mark Coleman wrote: > Greetings, > > I'm wondering how one can efficiently generalize the built-in > Complement function to return multiple occurrences of elements. For > instance, the current version generates > > a={1,2,2,3,4,4,4,4} > b={3,5,7} > > Complement[a,b]={1,2,4} > > I'm looking for a way to define > > myComplement[a,b]={1,2,2,4,4,4,4} > > My current code is very inefficient! > > Thanks, > > Mark > How about this: Select[a, FreeQ[b, #] &] -- Helen Read University of Vermont