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