Currently the calculation of circumcenters is based on a least-squares problem:
For all edges of the entity, formulate pairwise condition
|c - x_i|^2 = |x - x_j|^2, were (x_i, x_j) forms an edge
c = lambda * x, i.e.
c given in barycentric coordinates. Additionally require
sum(lambda) = 1.
The overdetermined system is solved with a qr-method with full pivoting, using Eigen, or row-pivoting using an own implementation. Both implementation fail for some cases, i.e. produce
This needs to be improved! Find a more stable and maybe more simple way of calculating the circumcenter for an (simplcial) entity of any dimension.