Re: HELP: How to do count to the SUB-LIST
- To: mathgroup at smc.vnet.net
- Subject: [mg82146] Re: HELP: How to do count to the SUB-LIST
- From: Norbert Marxer <marxer at mec.li>
- Date: Sat, 13 Oct 2007 03:52:25 -0400 (EDT)
- References: <fen5th$4ho$1@smc.vnet.net>
On 12 Okt., 08:57, zhen <wangzhen0... at gmail.com> wrote: > Hallo, everyone > > I am new to Mathematica, and I get one problem now, hope to get some > help here > > I got a list like this: > > {{0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 1, 1, 0, 0, 0, 1, 0, 0, 0}, > {0, 0, 0, 0, 1, 1, 0, 0, 2, 0}, {1, 0, 1, 0, 0, 1, 0, 1, 0, 0}, > {1, 3, 3, 4, 2, 2, 5, 3, 2, 1}, {7, 2, 2, 3, 4, 4, 0, 3, 1, 3}} > > I need to get a list to show the number of non zero number in each sub > list, as to say, I need to get a list like this: > > {0,3,3,4,10,9} > > Thanks alot! Hello Using Map and Count and your list (which is named lis here) the following code does what you want: (Count[#1, Except[0]] & ) /@ lis An alternative would be: (Length[Select[#1, #1 != 0 & ]] & ) /@ lis or without using pure functions: Clear[x, f1, f2]; f1[x_] := x != 0; f2[x_] := Length[Select[x, f1]]; Map[f2, lis] And so on Best Regards Norbert Marxer