Re: A Question about Combinatorica

*To*: mathgroup at smc.vnet.net*Subject*: [mg104817] Re: A Question about Combinatorica*From*: "Sjoerd C. de Vries" <sjoerd.c.devries at gmail.com>*Date*: Tue, 10 Nov 2009 06:04:07 -0500 (EST)*References*: <hd8sgh$60i$1@smc.vnet.net>

Dear Marwa Ali, I'm not sure whether I totally understand what you want to achieve. You can get all permutations of your list as follows: Permutations[{{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}}] Of course each permutation contains the same set of points, just in a different order. So, the SETS are all the same but the ORDERS are all different. You need to define what you mean with deleting similarities. Cheers -- Sjoerd On Nov 9, 12:56 pm, Marwa Abd El-Wahaab <m.a.elwah... at gmail.com> 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