RE : DeleteCases : several at once, conditions

*To*: mathgroup at smc.vnet.net*Subject*: [mg49378] RE : [mg49369] DeleteCases : several at once, conditions*From*: "Florian Jaccard" <florian.jaccard at eiaj.ch>*Date*: Sat, 17 Jul 2004 06:38:41 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

liste = {{1, 6, 7}, {3, 6, 9}, {1, 2, 11}, {3, 5, 9}, {2, 5, 6}, {2, 9, 11}, {2, 10, 11}, {3, 7, 9}, {5, 8, 11}, {3, 7, 9}, {7, 8, 9}, {2, 5, 12}, {2, 6, 10}, {2, 10, 11}, {1, 6, 9}, {6, 10, 12}, {3, 6, 12}, {2, 5, 12}, {3, 8, 9}, {9, 3, 4}, {1, 2, 7}}; if you want to delete all cases matching {1,_,_} or {9,_,_} : In[16]:= DeleteCases[liste, a_ /; MatchQ[a, {9, _, _}] || MatchQ[a, {1, _, _}]] Out[16]= {{3, 6, 9}, {3, 5, 9}, {2, 5, 6}, {2, 9, 11}, {2, 10, 11}, {3, 7, 9}, {5, 8, 11}, {3, 7, 9}, {7, 8, 9}, {2, 5, 12}, {2, 6, 10}, {2, 10, 11}, {6, 10, 12}, {3, 6, 12}, {2, 5, 12}, {3, 8, 9}} if you want to delete all cases where the first element is even : In[17]:= DeleteCases[liste, a_ /; EvenQ[First[a]]] Out[17]= {{1, 6, 7}, {3, 6, 9}, {1, 2, 11}, {3, 5, 9}, {3, 7, 9}, {5, 8, 11}, {3, 7, 9}, {7, 8, 9}, {1, 6, 9}, {3, 6, 12}, {3, 8, 9}, {9, 3, 4}, {1, 2, 7}} If you want to delete all cases where one element (or 2 ore 3) is even : In[28]:= DeleteCases[liste, a_ /; Or @@ EvenQ /@ a] Out[28]= {{3, 5, 9}, {3, 7, 9}, {3, 7, 9}} ans so on... regards F.Jaccard -----Message d'origine----- De : camerzone [mailto:camerzone at yahoo.com] Envoyé : vendredi, 16. juillet 2004 12:07 À : mathgroup at smc.vnet.net Objet : [mg49369] DeleteCases : several at once, conditions Suppose you have a list of lists, something like {{1, 6, 7}, {3, 6, 9}, {1, 2, 11}, {3, 5, 9}, {2, 5, 6}, {2, 9, 11}, { 2, 10, 11}, {3, 7, 9}, {5, 8, 11}, {3, 7, 9}, {7, 8, 9}, {2, 5, 12}, {2, 6, 10}, {2, 10, 11}, {1, 6, 9}, {6, 10, 12}, {3, 6, 12}, {2, 5, 12}, {3, 8, 9}, {1, 2, 7}} and you want to delete cases matching several different patterns, say {1,_,_} and {9,_,_} What's the most efficient way? Also, can you use conditions with DeleteCases? Say, I want to delete all cases containing even numbers? tks