distribution of n point on the unit circle



Hi,

I've been working on this problem for quite a while now and although it
didn't seem to be too difficult, I got stuck.

Consider n points distributed uniformly and independently on the unit
circle. What is the probability density function or the distribution
function for the smallest angle alpha such that all points are on a
sector of the unit circle with that opening angle.

For n=2 this is easy. alpha cannot be bigger than pi. Therefore
p.d.f.(alpha)=1/pi and d.f.(alpha)=alpha/pi.

In general, alpha must be smaller than or equal to 2pi*(n-1)/n. Using
Monte Carlo simulations I found out that for n=3 the p.d.f. is piecewise
linear with

3x/(2pi^2) for 0<=x<=pi
-9x/(2pi^2)+6/pi for pi<x<=4*pi/3

but I have no clue how to derive this analytically let alone how to
extend it to arbitrary n. Does anyone have an idea?

Ralf
.



Relevant Pages

  • Re: function arguments
    ... fis the probability density function for the joint distribution ... fis the probability density function for the conditional distribution ... y as a parameter rather than as a random quantity. ...
    (sci.stat.edu)
  • Re: Bell-curve distribution wanted
    ... pseudo-random numbers with a "bell curve" distribution. ... Conditions on the parameters are alpha> -1 ... and sigma is the standard ... Log normal distribution. ...
    (sci.math)
  • Splitting samples to minimize false positives?
    ... given alpha as to whether that sample came from that same distribution ... the false positive rate (fpr) will be alpha simply by chance. ... % a normal distribution to see how often it fails ...
    (sci.stat.math)
  • Re: RNG for non-uniform distributions
    ... distribution since that is the only RNG's I have seen. ... uniform(a, b) ... Conditions on the parameters are alpha> -1 ... mu is the mean, and sigma is ...
    (sci.math)
  • Re: RNG for non-uniform distributions
    ... Just curious as to if there are some algorithms for other than the uniform ... distribution since that is the only RNG's I have seen. ... Conditions on the parameters are alpha> -1 ... mu is the mean, and sigma is ...
    (sci.math)