-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
project.org] On Behalf Of R. Michael Weylandt
Sent: Friday, October 05, 2012 11:17 AM
To: Lorenzo Isella
Cc: r-help at r-project.org
Subject: Re: [R] Test for Random Points on a Sphere
On Fri, Oct 5, 2012 at 5:39 PM, Lorenzo Isella
<lorenzo.isella at gmail.com> wrote:
Dear All,
I implemented an algorithm for (uniform) random rotations.
In order to test it, I can apply it to a unit vector (0,0,1) in
coordinates.
The result is supposed to be a set of random, uniformly distributed,
on a sphere (not the point of the algorithm, but a way to test it).
This is what the points look like when I plot them, but other then
eyeballing them, can anyone suggest a test to ensure that I am really
generating uniform random points on a sphere?
Many thanks
Gut says to divide the surface into n bits of equal area and see if
the points appear uniformly in those using something chi-squared-ish,
but I'm not aware of a canonical way to do so.
Cheers,
Michael