Re: A Question about Combinatorica

*To*: mathgroup at smc.vnet.net*Subject*: [mg104791] Re: [mg104765] A Question about Combinatorica*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Tue, 10 Nov 2009 05:58:50 -0500 (EST)*Organization*: Mathematics & Statistics, Univ. of Mass./Amherst*References*: <200911091044.FAA05613@smc.vnet.net>*Reply-to*: murray at math.umass.edu

This does not require the Combinatorica package, at least in current versions of Mathematica: pts={{0.,0.,1.},{0.181636,0.559017,0.809017}, {-0.769421,0.559017,0.309017},{-0.769421,-0.559017,-0.309017}, {0.181636,-0.559017,-0.809017}}; Permutatations[pts]; (* suppress output *) Length[Permutations[pts]] 120 What do you mean "similarities"? You have 5 different points (as you can check by comparing the Length of Union[pts]). So there are exactly 120 (== 5! ) distinct permutations of those 5 objects. Marwa Abd El-Wahaab wrote: > Dear Sir > > I have a question about permutations of 5 points in 3D space . > > These 5 points are on the surface of a sphere of radius =1. > > These points are: > { {0., 0., 1.}, {0.181636, 0.559017, 0.809017}, {-0.769421, > 0.559017, 0.309017}, {-0.769421, -0.559017, -0.309017}, {0.181636, > -0.559017, -0.809017} } > > My question: > > What are all possible permutations for these 5 points ? > > What are the permutations after delete similarities? > > > I need your reply > > Thanks > > Marwa Ali > > -- 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**:**A Question about Combinatorica***From:*Marwa Abd El-Wahaab <m.a.elwahaab@gmail.com>