Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2001
*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 2001

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

Search the Archive

Sorting and Selecting in MultiLevel Lists?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg31163] Sorting and Selecting in MultiLevel Lists?
  • From: aes <siegman at stanford.edu>
  • Date: Sun, 14 Oct 2001 04:11:58 -0400 (EDT)
  • Organization: Stanford University
  • Sender: owner-wri-mathgroup at wolfram.com

Suppose I want to Sort, or Select from, a multilevel list, e.g.

        myList =  { {x1,y1},  {x2,y2},  {x3,y3}, . . . }

with a Sort or Select criterion that's some function of the xn and yn values

For example, I can sort the above list on the value of x^2 + y^2 by using

    Sort[myList, (Take[#1, 1][[1]]^2 + Take[#1, 2][[1]]^2) < 
                        (Take[#2, 1][[1]]^2 + Take[#2, 2][[1]]^2) &]

Question:  Is there an easier way to get at the "x" and "y" values associated 
with the #1 and #2 arguments in Sort, or with the # argument in Select, than the 
awkward   Take[#,m][[n]]   notation used here?


  • Prev by Date: style sheeting
  • Next by Date: Re: Solving simultaneous equations with inequalities
  • Previous by thread: style sheeting
  • Next by thread: Re: Sorting and Selecting in MultiLevel Lists?