Re: expanding a list
- To: mathgroup at smc.vnet.net
- Subject: [mg42614] Re: [mg42593] expanding a list
- From: Tomas Garza <tgarza01 at prodigy.net.mx>
- Date: Fri, 18 Jul 2003 05:25:08 -0400 (EDT)
- References: <200307170745.DAA23026@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
The first thing that comes to my mind (and no doubt it will be much improved
by other members of this group) is:
In[1]:=
a = MapThread[List, {plist, flist}]
Out[1]=
{{0.252, 7}, {0.252, 5}, {0.257, 6}, {0.235, 4}}
In[2]:=
Flatten[(Table[#[[1]], {#[[2]]}] & ) /@ a]
Out[2]=
{0.252,0.252,0.252,0.252,0.252,0.252,0.252,0.252,0.252,0.252,0.252,0.252,0.\
257,0.257,0.257,0.257,0.257,0.257,0.235,0.235,0.235,0.235}
Tomas Garza
Mexico City
----- Original Message -----
From: "Alan Kelly" <Alan.Kelly at tcd.ie>
To: mathgroup at smc.vnet.net
Subject: [mg42614] [mg42593] expanding a list
> Hi all,
> I believe that this is a rather elementary question, but I am not
> aware of a simple, elegant and efficient solution. I have searched
> the MathGroup archive, but with no success.
>
> I have two lists - both of the same length. The first contains a
> list of probabilities. For example, suppose the list length is 4
> (although in practice it would be much longer) and is of the
> following form:
> plist = {0.252, 0.252, 0.257, 0.235}.
> The second contains a list of integers:
> flist = {7,5,6,4}.
> I wish to take the first element of plist and replicate that value
> using the first element of flist. Similarly for the remaining
> elements.
> I should finish with a list of length 7+5+6+4 or 22.
> Any suggestion please.
> Many thanks,
> Alan Kelly
> Trinity College Dublin
>
>
- References:
- expanding a list
- From: Alan Kelly <Alan.Kelly@tcd.ie>
- expanding a list