Sam Sturgess s.sturgess at
Fri Mar 3 14:34:09 PST 2000


I got this email address from the follwing web page

I was looking for exactly what the question asks, ie

I am searching for a numerically stable algorithm to calculate the radius r
(and perhaps the center m) of the circumsphere of a tetrahedron in three
dimensions, given by the coordinates of the vertices a, b, c, d in R^3.

I am using the formula in a Delaunay Tessellation of a randomly packed bed
of spheres.  Having worked through the formula given though I am confused,
as for a simple tetrahedron with vertex coordinates


I found the centre to lie outside the tetrahedron at (0.5,0.5,0.5).  

If you could explain this I'd greatly appreciate it.  Otherwise if you know
of any references (such as a geometry text) that contains such a formula
and relevant explanations then I appreciate that as well.  


Sam Sturgess (Masters Research)
Dept Mining Mineral Materials Engineering
University of Qld, Australia

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