These functions provide tests for classes of generalized ellipsoids in the
(U, D) representation, based on the numbers of positive, zero and infinite
singular values in D.
They are included here mainly as computational definitions of the terms
‘bounded’ for an ellipsoid with finite extent,
‘fat’, for a bounded ellipsoid with non-empty interior,
‘flat’, for degenerate (singular) ellipsoids
in \(R^p\) with empty interior.