RE: more elements in a list
- To: mathgroup at smc.vnet.net
- Subject: [mg32390] RE: [mg32241] more elements in a list
- From: "Wolf, Hartmut" <Hartmut.Wolf at t-systems.de>
- Date: Fri, 18 Jan 2002 00:17:36 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Merkat,
There have been quite a few answers on this problem. Here is another one:
In[1001]:=
Thread[Unevaluated[NestList[Sequence,Join[a,b,c],Join[1,4,3]]],Join]
Out[1001]=
{a,a,b,b,b,b,b,c,c,c,c}
You have to specify repetions then, instead of number of occurrences. If you
don't like this, add the precomputation for that:
In[2002]:=
Unevaluated[
Thread[Unevaluated[NestList[Sequence,xx,yy]],Join]]/.
{xx->Join@@{a,b,c}, yy->Join@@({2,5,4}-1)}
Out[2002]=
{a,a,b,b,b,b,b,c,c,c,c}
But, alas, this solution will not allow for zero occurrances ;-)
--
Hartmut
> -----Original Message-----
> From: merkat [SMTP:cabanc at hotmail.com]
To: mathgroup at smc.vnet.net
> Sent: Wednesday, January 09, 2002 9:18 AM
> To: mathgroup at smc.vnet.net
> Subject: [mg32241] more elements in a list
>
> Hi ,
>
> How do I multiply the number of elements in a list?
> I have the lists:
> {a,b,c} and
> {2,5,4}
>
> the result should be:
> {a,a,b,b,b,b,b,c,c,c,c}
>
> Merkat