DOI: 10.68381/jca21001 ISSN: 0944-6532

Conic Separation of Finite Sets. I: The homogeneous case

Annabella Astorino, Manlio Gaudioso, Alberto Seeger

This work addresses the issue of separating two finite sets in

\mathbb{R}^n R n
by means of a suitable revolution cone
\Gamma (z,y,s)= \{x \in \mathbb{R}^n: s\,\Vert x-z\Vert - y^T(x-z)=0\}. Γ ( z , y , s ) = { x ∈ R n : s   ∥ x − z ∥ − y T ( x − z ) = 0 } .
The specific challenge at hand is to determine the aperture coefficient
s s
, the axis
y y
, and the apex
z z
of the cone. These parameters have to be selected in such a way as to meet certain optimal separation criteria. Part I of this work focusses on the homogeneous case in which the apex of the revolution cone is the origin of the space. The homogeneous case deserves a separated treatment, not just because of its intrinsic interest, but also because it helps to built up the general theory. Part II of this work concerns the non-homogeneous case in which the apex of the cone can move in some admissible region. The non-homogeneous case is structurally more involved and leads to challenging nonconvex nonsmooth optimization problems.