Re: Sorting complex points
- To: mathgroup at smc.vnet.net
- Subject: [mg55891] Re: [mg55874] Sorting complex points
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Sat, 9 Apr 2005 03:55:30 -0400 (EDT)
- Organization: Mathematics & Statistics, Univ. of Mass./Amherst
- References: <200504080537.BAA25196@smc.vnet.net>
- Reply-to: murray at math.umass.edu
- Sender: owner-wri-mathgroup at wolfram.com
?Sort
Sort[list] sorts the elements of list into canonical
order. Sort[list, p] sorts using the ordering function \
p. More...
Clicking the More hyperlink takes you to The HelpBrowser help about
Sort. Under the Further Examples there, you'll see, for example:
Sort[{-8, -5, 6, 9}, #1^2 < #2^2 & ]
So for your situation:
sortByArg[z_List] := Sort[z, Arg[#1] < Arg[#2] &]
For example:
myzs = {-1 + 9I, 0.5I, -I, -4, 2 + 3I};
sortByArg[myzs]
{-I, 2 + 3*I, 0.5*I, -1 + 9*I, -4}
OT wrote:
> Hi all,
>
> I'm trying to sort lists of random complex points on the unit circle
> using their angles as criterion to sort them: I mean, if
> z=Cos[a]+I*Sin[a] and w=Cos[b]+I*Sin[b]( 0<=a,b<2*Pi ),
> I want z<w if a<b;
>
> how can i do that?
>
> I tried to define Angle[z] as a piecewise funztion, but I still don't
> understand how to use it with Sort...
>
> Thanks,
>
> andrea
>
>
--
Murray Eisenberg murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2859 (W)
710 North Pleasant Street fax 413 545-1801
Amherst, MA 01003-9305
- References:
- Sorting complex points
- From: OT <montoz@iol.it>
- Sorting complex points