Re: Parts of a list
- To: mathgroup at smc.vnet.net
- Subject: [mg15440] Re: [mg15430] Parts of a list
- From: "C. Frey" <Clemens.Frey at uni-bayreuth.de>
- Date: Mon, 18 Jan 1999 04:21:44 -0500
- Sender: owner-wri-mathgroup at wolfram.com
Hallo, for this task you can use both Select and Cases; in the latter case you have to use a conditional pattern. Just look at the following examples: x={{1,0},{2.5, .5},{3,0},{0,2}}; Then use Select[x,#[[2]]!=0&] or Cases[x,{_,y_}/;y!=0] Hope that helped Clemens ------------------------------------------------------------ Clemens Frey Doctoral Fellow at the Department of Mathematics/BITOEK University of Bayreuth(Germany) clemens.frey at uni-bayreuth.de http://www.bitoek.uni-bayreuth.de/~Clemens.Frey ------------------------------------------------------------ On Wed, 13 Jan 1999, Hossein Kazemi wrote: > I have a list (matrix) that looks like this > > x={{1,0},{2.5, .5},{3,0},{0,2}} > > Now I want to eliminate those vectors that have zero for the second > case. That is, I want to get > > {{2.5, .5},{0,2}}. > > Is there a quick way of doing this? > I tried to apply Select to this but could not get it to work. > > Thanks for your help. > > Hossein Kazemi > UMass > kazemi at som.umass.edu > > > >