Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2002
*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 2002

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

Search the Archive

How Do You Reduce Multiple Elements in a List?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg33863] How Do You Reduce Multiple Elements in a List?
  • From: Bob Harris <nitlion at mindspring.com>
  • Date: Sat, 20 Apr 2002 02:49:57 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

Howdy,

This seems like such a simple thing, yet I've search through the big book
trying to figure it out.  Perhaps someone can help me...

Given a list of integers that generally contains the same number many times,
I'd like to reduce it to a list that just gives me the number/count pairs.
For example, I'd like to convert the list
   {1, 1, 1, 1, 1, 2, 2, 2, 4, 4, 4, 4, 4, 4}
into
   {{1,5}, {2,3}, (4,6}}

Is there a built-in function to do this?  Seems like a histogramming
operation, but I get no useful matches from ?*Hist*.

Thanks,
Bob H



  • Prev by Date: Re: Can I do MultipleListPlot with Color?
  • Next by Date: Drawing a Glass Cylinder?
  • Previous by thread: Problem using NonlinearFit/Regress?
  • Next by thread: Re: How Do You Reduce Multiple Elements in a List?