Noise Sphere
- To: mathgroup at smc.vnet.net
- Subject: [mg25316] Noise Sphere
- From: Geoffrey Steeves <gsteeves at gpu.srv.ualberta.ca>
- Date: Tue, 19 Sep 2000 03:45:46 -0400 (EDT)
- Organization: University of Alberta
- Sender: owner-wri-mathgroup at wolfram.com
: In studying whether a sequence of numbers is random, one can construct : what is called a Noise : Sphere(http://mathworld.wolfram.com/NoiseSphere.html). When I tried this : out, I got a non-uniform distibution of points concentrated along : the verticle axis (phi ~= 0) of the sphere. Initially I thought that this : was an artifact of my pseudo-random number generator, but I later tried : this out with "real" random numbers and got the same distribution. : Looking at the mapping(as it is shown on the web page): : theta = 2 * Pi * Random[] : phi = Pi * Random[] : r = Sqrt[Random[]] : I thought that the problem was with the distribution in phi. Is this a : mistake in the map? Or am I misunderstanding the what a Noise spehere is : supposed to be? Thanks for the help! : -- : ___________________________________________________________________________ : Geoff Steeves // University of Alberta Physics // : http://www.ualberta.ca/~gsteeves : ---------------------------------------------------------------------------