Re: List Manipulation

*To*: mathgroup at smc.vnet.net*Subject*: [mg124915] Re: List Manipulation*From*: "Oleksandr Rasputinov" <oleksandr_rasputinov at ymail.com>*Date*: Sun, 12 Feb 2012 05:01:00 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jh6k3l$jrc$1@smc.vnet.net>

On Sat, 11 Feb 2012 20:46:45 -0000, Murta <rodrigomurtax at gmail.com> wrote: > Hi All > > I'm looking some better solution for the below list manipulation: > l1={a,b,c}; > l2={{1,2,3},{4,5,6},{7,8,9}}; > output = {{a,1},{a,2},{a,3},{b,4},{b,5},{b,6},{c,7},{c,8},{c,9}} > It's a simple distributions of terms. > > I used this solution, but I think it's not an elegant one: > > f[a_, b_] := Flatten[{a, #}] & /@ b; > MapThread[f, {l1, l2}] // Flatten[#, 1] & > > Some clue? > Maybe with Outer or Inner? > Thanks in advance! > Murta > Undoubtedly there are many ways to accomplish this. Here's one using Distribute: MapThread[Distribute[{##}, List, List, Sequence] &, {l1, l2}] {{a, 1}, {a, 2}, {a, 3}, {b, 4}, {b, 5}, {b, 6}, {c, 7}, {c, 8}, {c, 9}} and here's one using Inner: Inner[List, l1, Transpose[l2], Sequence] {{a, 1}, {b, 2}, {c, 3}, {a, 4}, {b, 5}, {c, 6}, {a, 7}, {b, 8}, {c, 9}}