Re: reliably sort?
- To: mathgroup at smc.vnet.net
- Subject: [mg123773] Re: reliably sort?
- From: David Bailey <dave at removedbailey.co.uk>
- Date: Sun, 18 Dec 2011 04:37:26 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <jca06e$a35$1@smc.vnet.net> <201112150956.EAA23025@smc.vnet.net> <op.v6js80k5tgfoz2@bobbys-imac.local> <jcf8et$6v2$1@smc.vnet.net>
On 16/12/2011 11:01, Nasser M. Abbasi wrote: > On 12/15/2011 2:44 PM, DrMajorBob wrote: >> Michael, >> >> Sorry, but no. Union always sorts. >> >> Bobby >> > > You mean Mathematica's Union[] always sorts, right? Because > at school the teacher kept telling us that a set has no > implied order between its elements. It is just a collection > of elements. But a sequence has an order. > > Result of a Union is a set. Hence one can not talk about > a set being sorted. The result is not a set then, but a > sequence, but the result of a Union should be a set. > > --Nasser > > > Lists can mean many things in Mathematica: Vectors (nested lists represent matrices or tensors) Actual lists Sets Anything else you want to represent as a list You know what any particular list means, but Mathematica doesn't care. Mathematica functions that operate on any of these, are defined as operations on lists. David Bailey http://www.dbaileyconsultancy.co.uk
- References:
- Re: Does Union[] reliably sort?
- From: "Nasser M. Abbasi" <nma@12000.org>
- Re: Does Union[] reliably sort?