In article <Ssmdnf9hNKUwITnZnZ2dnUVZ_q6dnZ2d@speakeasy.net>, Hatto von Aquitanien <abbot@AugiaDives.hre> wrote:
> Virgil wrote: > > > It was, I believe, the sphere x^2 + y^2 + (z-1)^2 = 1 in R^3 which > > Hatto himself originally referred to, with and without the point > > (0,0,2). Or possibly one with a different radius but still tangent to > > the x-y plane. > > My original example was slightly in error because I put the center at the > origin. Hence my comment about it being in need of a trivial modification. > The model I used to generate the graphics put the center at z=0.5 with a > radius of 1.
So your modification conforms to my model with r = 0.5
