Re: How do I use Select[list,condition]?

*To*: mathgroup at smc.vnet.net*Subject*: [mg4546] Re: How do I use Select[list,condition]?*From*: Nate Brixius <brixius at cs.uiowa.edu>*Date*: Wed, 7 Aug 1996 04:17:52 -0400*Organization*: The University of Iowa*Sender*: owner-wri-mathgroup at wolfram.com

Jason Welter wrote: > > I have a list that looks like: > > data = {{1,1,a,4,5,6},{2,1,a,2,3,4},{3,1,a,7,8,9}, > {1,2,b,4,5,6},{2,2,b,2,3,4},{3,2,b,7,8,9}, > {1,3,c,4,5,6},{2,3,c,2,3,4},{3,3,c,7,8,9}} > > and I want to pick out the lists that have a 2 as the second element > of the list. I tried something like: > > data1 = Select[data,data[[#,2]]==2]; > > but this doesn't work. How do I do it? Try the following: data = {{1,1,a,4,5,6},{2,1,a,2,3,4},{3,1,a,7,8,9}, {1,2,b,4,5,6},{2,2,b,2,3,4},{3,2,b,7,8,9}, {1,3,c,4,5,6},{2,3,c,2,3,4},{3,3,c,7,8,9}} data1 = Select[data,(#[[2]]==2)&] Output: Out[58]= {{1, 1, a, 4, 5, 6}, {2, 1, a, 2, 3, 4}, {3, 1, a, 7, 8, 9}, {1, 2, b, 4, 5, 6}, {2, 2, b, 2, 3, 4}, {3, 2, b, 7, 8, 9}, {1, 3, c, 4, 5, 6}, {2, 3, c, 2, 3, 4}, {3, 3, c, 7, 8, 9}} Out[59]= {{1, 2, b, 4, 5, 6}, {2, 2, b, 2, 3, 4}, {3, 2, b, 7, 8, 9}} I hope this helps. Nate ==== [MESSAGE SEPARATOR] ====