Add uniform_inside_sphere_distribution

[Marc Glisse]

On Wed, 5 Nov 2014, Ed Smith-Rowland wrote:

> On 11/05/2014 04:25 PM, Marc Glisse wrote:
>> On Wed, 5 Nov 2014, Ed Smith-Rowland wrote:
>> 
>>> Like the uniform_on_sphere_distribution which is used inside, the 
>>> 2-dimensional case uses rejection
>> 
>> Could you point out where in the code you are special-casing dimension 2? 
>> Somehow I can't see it in the patch.
>> 
> My miscommunication.  Sorry.
>
> The special casing - and all the hard work - is done by the contained 
> uniform_on_sphere_distribution.

In dimension 2, uniform_on_sphere_distribution generates a uniform random 
point in the unit disk and projects it to the circle. Using that + one 
more random number to regenerate a uniform random point in the disk seems 
wasteful to me.

-- 
Marc Glisse