Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2006
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2006

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Extract values and multilpicities from list

  • To: mathgroup at smc.vnet.net
  • Subject: [mg64859] Re: Extract values and multilpicities from list
  • From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
  • Date: Mon, 6 Mar 2006 05:01:01 -0500 (EST)
  • Organization: The Open University, Milton Keynes, UK
  • References: <due96k$ach$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Dr. Wolfgang Hintze wrote:
> Given a list of integers which may repeat, e.g.
> 
> lstIn = {2,3,4,4,2,1,1,5,4}
> 
> provide a list of different values and their respective multiplicities,
> in the example,
> 
> LstOut= {{1,2},{2,2},{3,1},{4,3},{5,1}}
> 
> Who finds the shortest function doing this task in general?
> 
> Thanks.
> 
> Best regards,
> Wolfgang
> 
Hi Wolfgang,

What about the following one liner?

In[1]:=
lstIn = {2, 3, 4, 4, 2, 1, 1, 5, 4};

In[2]:=
Flatten /@ Thread[
    {Flatten /@ ({Union[#1], Length[#1]} & ) /@
       Split[Sort[lstIn]]}]

Out[2]=
{{1, 2}, {2, 2}, {3, 1}, {4, 3}, {5, 1}}

Best regards,
/J.M.


  • Prev by Date: Compile Fourier (2)
  • Next by Date: Re: MatrixForm to JPG
  • Previous by thread: Re: Extract values and multilpicities from list
  • Next by thread: Re: Extract values and multilpicities from list