Re: DeleteCases and multiple patterns
- To: mathgroup at smc.vnet.net
- Subject: [mg93964] Re: DeleteCases and multiple patterns
- From: Albert Retey <awnl at gmx-topmail.de>
- Date: Sun, 30 Nov 2008 06:57:47 -0500 (EST)
- References: <ggr217$e21$1@smc.vnet.net>
Hi, > > I have, say a list of list. Each element is a list of length 3 i.e. > > myList={{x1,y1,z1},{x2,y2,z2},...{xN,yN,zN}} > > Now, let's say I want to delete from this list the element which have > x=2 and 3 using DeleteCases. > This works : > > DeleteCase[myList,{2,_,_}] > DeleteCases[myList,{3,_,_}] > > but I would like to use > > DeleteCases[myList,{{2,_,_},{3,_,_}}] > > and this does not work... > > How do I combine multiple patterns in DeleteCases ? I think you can't, but there is no need to do that, since you can formulate patterns that match more than one case with Alternatives, or its short form | . So this should do what you want: DeleteCases[myList,{2,_,_}|{3,_,_}] or, in this case: DeleteCases[myList,{2|3,_,_}] hth, albert