Re: A Question about Combinatorica
- To: mathgroup at smc.vnet.net
- Subject: [mg104798] Re: [mg104765] A Question about Combinatorica
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Tue, 10 Nov 2009 06:00:10 -0500 (EST)
- Reply-to: hanlonr at cox.net
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}};
p1 = Permutations[pts];
Length[p1] == 5!
True
Guessing what you mean by similarities:
pts2 = Union[pts,
SameTest -> (Abs[#1] == Abs[#2] &)]
{{-0.769421, -0.559017, -0.309017}, {0., 0., 1.},
{0.181636, -0.559017, -0.809017}}
p2 = Permutations[pts2];
Length[p2] == 3!
True
Bob Hanlon
---- Marwa Abd El-Wahaab <m.a.elwahaab 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