Re: For Routine to Map Routine
- To: mathgroup at smc.vnet.net
- Subject: [mg70449] Re: For Routine to Map Routine
- From: Peter Pein <petsie at dordos.net>
- Date: Mon, 16 Oct 2006 02:36:35 -0400 (EDT)
- References: <egse9i$css$1@smc.vnet.net>
Benedetto Bongiorno schrieb: > To All, > > Dimensions of ans01 is 2185850 by 5. > I am looking to convert my For routine to the more efficient Map routine > > n=Length[ans01] > fo={}; > > For[i=1, i<n, i++, > If[ans01[[i,1]] == ans01[[i+1,1]], > AppendTo[fo, ans01[[1]]]]; > > I tried > Map[If[#[[1]] == #[[1]],#]&,ans01]; > > But it does not work. > > Thank you > > Ben > > Hi Ben, I do not understand the use of your For-loop. But I think it does the same as Table[First[ans01],{Count[MapThread[Equal,Through[{Most,Rest}[ans01[[All,1]]]]],True]}] did you mean eventually something like: lst={1,2,3,3,4,4,4,4,5}; Flatten[Rest/@Split[lst]] --> {3,4,4,4} ?? Peter