Re: How to do count for sub list?????
- To: mathgroup at smc.vnet.net
- Subject: [mg82192] Re: How to do count for sub list?????
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Sun, 14 Oct 2007 06:15:01 -0400 (EDT)
- Organization: The Open University, Milton Keynes, UK
- References: <fen5rk$4gi$1@smc.vnet.net>
wangzhen0829 at gmail.com wrote:
> I am new to Mathematica, and now I have a problem with it, hope to get
> some help from here.
>
> I have a
>
> {{0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, {
> 0, 0, 0, 1, 0, 0, 0, 0, 0, 1}, {1, 0, 0, 0, 0, 0, 0, 0, 0, 0}, {
> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, {
> 0, 0, 0, 0, 0, 0, 0, 0, 1, 0}, {0, 0, 0, 0, 1, 0, 0, 0, 0, 0}}
>
> I need to get a list which represent the number of NON-zero number in
> each sublist.
>
> I should get a list like:
>
> {0,0,1,1,0,0,1,1}
-------^
I believe that the third entry should be a two rather than a one.
Assuming that you want to count the numbers of ones within each
sublists, you could use, among many other way, one of the following:
In[1]:= lst = {{0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0,
0, 0, 0}, {0, 0, 0, 1, 0, 0, 0, 0, 0, 1}, {1, 0, 0, 0, 0, 0, 0, 0,
0, 0}, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0,
0, 0}, {0, 0, 0, 0, 0, 0, 0, 0, 1, 0}, {0, 0, 0, 0, 1, 0, 0, 0, 0,
0}};
Count[#, 1] & /@ lst
Total[Transpose@lst]
Plus @@@ lst
Out[2]= {0, 0, 2, 1, 0, 0, 1, 1}
Out[3]= {0, 0, 2, 1, 0, 0, 1, 1}
Out[4]= {0, 0, 2, 1, 0, 0, 1, 1}
Regards,
--
Jean-Marc