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: Sorting Rows of a Matrix

  • To: mathgroup at smc.vnet.net
  • Subject: [mg65119] Re: Sorting Rows of a Matrix
  • From: dh <dh at metrohm.ch>
  • Date: Wed, 15 Mar 2006 06:28:35 -0500 (EST)
  • References: <dv69a6$o6l$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Hi Greg,
you can solve thhis problem by using the second argument of Sort (see 
the manual). E.g. r will choose the sorting row:

m={{1,3},{2,2},{3,1}};
r=1;
Sort[m, #1[[r]] < #2[[r]] &]

with r=2 we get: {{1, 3}, {2, 2}, {3, 1}}
with r=2 we get: {{3, 1}, {2, 2}, {1, 3}}

Daniel

Gregory Lypny wrote:
> Hello everyone,
> 
> How can I sort the rows of a matrix by using one or more of the  
> columns as sort keys just like in a spreadsheet?  For example, if  
> matrix M is 12 x 2 with numbers in the first column and unordered  
> month numbers in the second, how would I order the rows by month?
> 
> 	Regards,
> 
> 		Greg
> 


  • Prev by Date: Re: Writing regular text?
  • Next by Date: Re: Sorting Rows of a Matrix
  • Previous by thread: RE: Sorting Rows of a Matrix
  • Next by thread: Re: Sorting Rows of a Matrix