Re: Selecting Rows Based on Column Values
- To: mathgroup at smc.vnet.net
- Subject: [mg101533] Re: Selecting Rows Based on Column Values
- From: Peter Breitfeld <phbrf at t-online.de>
- Date: Thu, 9 Jul 2009 01:59:06 -0400 (EDT)
- References: <h31uoe$bra$1@smc.vnet.net>
cynthia wu wrote:
> I've been trying to use the Select Command to select only the rows
> that have the a specific value in a specific column. I have, for
> example, the following matrix (4x3):
>
> tester={{1, 3, 1}, {3, 1, 0}, {4, 2, 1}, {5, 6, 2}}
>
> I want to select the rows that have values ==1 in the 3rd column.
> I've tried:
>
> select(tester, #[[All,3]]==1&), but I get an error saying that my
> request violates the matrix boundaries.
>
> The desired output should be: {{1,3,1}, {4,2,1}}.
>
> Any thoughts would be greatly appreciated. Thanks!
>
Cynthia,
You might use a pattern instead:
Cases[tester,{__,1}]
Out= {{1, 3, 1}, {4, 2, 1}}
--
_________________________________________________________________
Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de