Re: Getting stuck with finding an elegant solution without global variables
- To: mathgroup at smc.vnet.net
- Subject: [mg124814] Re: Getting stuck with finding an elegant solution without global variables
- From: Ray Koopman <koopman at sfu.ca>
- Date: Wed, 8 Feb 2012 05:28:44 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <jgqpmc$n0p$1@smc.vnet.net>
On Feb 7, 1:08 am, Fredob <fredrik.dob... at gmail.com> wrote:
> Hi,
>
> I am trying to find an elegant solution, i.e. without a global
> variable to the following problem:
>
> Given a list, e.g. {1,2,3,4}, create a new list where each element is
> a function of the "i th" element and the rest of the list, e.g.
>
> Branch[Elem_, List_] := Elem + Cases[List, Except[Elem]]
>
> The the result would be {{3, 4, 5}, {3, 5, 6}, {4, 5, 7}, {5, 6, 7}}
>
> I have used Map[f, List] but then I have to use a global variable in f
> to access the list itself, e.g. BranchG[Elem_] := Elem + Cases[List,
> Except[Elem]]
In[1]:= f[a_List] := a + Array[Delete[a,#]&,Length@a]
In[2]:= f@{1,2,3,4}
Out[2]= {{3,4,5},{3,5,6},{4,5,7},{5,6,7}}