Re: "expanding a list"
- To: mathgroup at smc.vnet.net
- Subject: [mg57878] Re: "expanding a list"
- From: Peter Pein <petsie at dordos.net>
- Date: Sat, 11 Jun 2005 03:35:32 -0400 (EDT)
- References: <d8bd00$fj0$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Mark Coleman schrieb:
> Greetings,
>
> I'd like to construct a list as follows. Say I have a list of reals
> {x1,x2,x3,...xn}, and another list of integers {r,s}. I'd like to
> make a new list
>
> {{x1,x1,x1,...},{x2,x2,x2....},{x3,x3,x3,...},....,{xn,xn,xn,...}},
> where the first sublist is of length r, and the remaining sublists
> are of length s.
>
>
> Thanks,
>
> -Mark
>
>
>
This code:
newList[xi_List, {n1_Integer, n2_Integer}] :=
Join[{Table[First[xi], {n1}]}, (Table[#1, {n2}] & ) /@ Rest[xi]]
newList[{1, 2, 3, 4}, {5, 2}]
-> {{1, 1, 1, 1, 1}, {2, 2}, {3, 3}, {4, 4}}
should do it.
--
Peter Pein
Berlin