Re: Fw: Re: Multiplying permutations
- To: mathgroup at smc.vnet.net
- Subject: [mg41934] Re: Fw: Re: Multiplying permutations
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Wed, 11 Jun 2003 03:49:14 -0400 (EDT)
- Organization: The University of Western Australia
- References: <bc1jol$bn9$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
In article <bc1jol$bn9$1 at smc.vnet.net>, "Dr. Wolfgang Hintze" <weh at snafu.de> wrote: > Question: is it also possible to use the normal product sign in the form > of a space, i.e. > > p q > > instead of > > p . q ? Yes -- but it is not usually a good idea. See http://physics.uwa.edu.au/pub/Mathematica/MathGroup/SpaceAsOperator.nb. Cheers, Paul > Mihajlo Vanevic wrote: > > > Wolfgang, > > > > I tried to send you a private e-mail, > > but it didn't reach you... > > > > So, this time, I'm going to post it to the MathGroup too :) > > > > Mihajlo > > > > ************* THIS IS A FORWARD MESSAGE **************** > > * At 2003-06-03, 15:13:55 > > * Mihajlo Vanevic, mvane at EUnet.yu wrote: > > *************************************************************** > > > >>In[]:== > >>Clear[CenterDot] > >> > >>In[]:== > >>SetAttributes[CenterDot, {Flat, OneIdentity}] > >> > >>In[]:== > >>p_=q_ :== q[[p]]; > >> > >>In[]:== > >>{3, 1, 2}={2, 1, 3} > >> > >>Out[]== > >>{3, 2, 1} > >> > >>In[]:== > >>({3, 1, 2}={2, 1, 3})={3, 2, 1} > >> > >>{3, 1, 2}=({2, 1, 3}={3, 2, 1}) > >> > >>{3, 1, 2}={2, 1, 3}={3, 2, 1} > >> > >> > >>You can enter = symbol with Esc . Esc (on Windows) > >> > >>Regards, > >> Mihajlo Vanevic > >> mvane at EUnet.yu > >> 2003-06-03 > >> > >>************************************************************** > >>* At 2003-06-03, 07:13:00 > >>* Dr. Wolfgang Hintze, weh at snafu.de wrote: > >>************************************************************** > >> > >>>Is there a simple command in Mathematica to multiply two permutations, > > >>>i.e. to carry out one after the other? > >>> > >>>I looked at the packages DiscreteMath`Permutations` and > >>>DiscreteMath`Combinatorica` but couldn't find it. > >>> > >>>Example > >>> > >>>p == {3,1,2} mapping: 1->3, 2->1, 3->2 > >>>q == {2,1,3} mapping: 1->2, 2->1, 3->3 > >>>p.q == mappings (p first, then q) > >>> [1-p->3-q->3, 2-p->1-q->2, 3-p->2-q->1] > >>>== {3,2,1} > >>> > >>>Any help appreciated > >>> > >>>Wolfgang > >>> > >>************************************************************** > >> > > *************************************************************** > > > > -- Paul Abbott Phone: +61 8 9380 2734 School of Physics, M013 Fax: +61 8 9380 1014 The University of Western Australia (CRICOS Provider No 00126G) 35 Stirling Highway Crawley WA 6009 mailto:paul at physics.uwa.edu.au AUSTRALIA http://physics.uwa.edu.au/~paul