Re: Parts of a list
- To: mathgroup at smc.vnet.net
- Subject: [mg15458] Re: [mg15430] Parts of a list
- From: "Arnold Knopfmacher" <arnoldk at gauss.cam.wits.ac.za>
- Date: Mon, 18 Jan 1999 04:22:00 -0500
- Organization: CAM,University ofthe Witwatersrand
- Sender: owner-wri-mathgroup at wolfram.com
Regarding your problem (at end of message), this works In[3]:= x //.{a___,{b_,0},c___}->{a,c} Out[3]= {{2.5,0.5},{0,2}} Or using Select In[8]:= Select[{#},#[[2]]!=0&]& /@x Out[8]= {{},{{2.5,0.5}},{},{{0,2}}} In[9]:= Flatten[%,1] Out[9]= {{2.5,0.5},{0,2}}. Cheers Arnold Knopfmacher > Date: Wed, 13 Jan 1999 20:57:41 -0500 > From: "Hossein Kazemi" <kazemi at som.umass.edu> To: mathgroup at smc.vnet.net > 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}}.