Re: Combinations
- To: mathgroup at smc.vnet.net
- Subject: [mg30821] Re: Combinations
- From: "Graeme Byrne" <g.byrne at bendigo.latrobe.edu.au>
- Date: Wed, 19 Sep 2001 00:17:17 -0400 (EDT)
- Organization: La Trobe University
- References: <9nh2jh$ml$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Dana, try Count[Permutations[{a, b, c, d, e, f}], _ ] for the number of permutations of a list of things and Binomial[a,b] for the number of combinations of a things taken b at a time Graeme "Dana" <ng_only at hotmail.com> wrote in message news:9nh2jh$ml$1 at smc.vnet.net... > Hello. I have Mathematica 4.1 > > In a Program like Excel, or a hand-held calculator, one can return the > number of combinations and permutations. > > However, I can not find an equivalent function in Mathematica. > For example, Permutations[ ] returns a long list of all the "Actual" > permutations. > I am looking for just the final number. > If there is one, could you include 'how' you found it. I have looked > everywhere. > I know DiscreteMath`Combinatorica` has some stuff in it, but the Help system > appears not to explain many of them. > > I can write a custom function, but I am curious to find out if this function > is built in to Mathematica. > > I hope the answer is not to take the Length[ ] of a rather long list. > > TIA. Dana > > (I posted this question a month ago, but it never showed up in the > newsgroup, or in the archives. > I hope I am not doing something wrong.) > > > > >