gellipsoid (Q110736)

Represents generalized geometric ellipsoids with the "(U,D)" representation. It allows degenerateand/or unbounded ellipsoids, together with methods for linear and duality transformations, and for plotting.Thus ellipsoids are naturally extended to include lines, hyperplanes, points, cylinders, etc.This permits exploration of a variety to statistical issues that can be visualized using ellipsoidsas discussed by Friendly, Fox & Monette (2013), Elliptical Insights: Understanding Statistical Methods Through Elliptical Geometry <doi:10.1214/12-STS402>.