LANS Publications
"The Penalty Interior-Point Method Fails to Converge"
S. Leyffer
Preprint ANL/MCS-P1091-0903
Preprint Version: [pdf]
Equilibrium equations in the form of complementarity conditions often appear as constraints in optimization problems. Problems of this type are commonly referred to as mathematical programs with complementarity constraints (MPCCs). A popular method for solving MPCCs is the penalty interior-point algorithm (PIPA). This paper presents a small example for which PIPA converges to a nonstationary point, providing a counterexample to the established theory. The reasons for this adverse behavior are discussed.