A New Nonlinear Equations Test Problem

This presents a set of test problems for nonlinear equations and nonlinear least-squares algorithms. These problems, sent to us by C.V. Nelson of the Maine Medical Center, come from a dipole model of the heart. They are 6 x 6 or 8 x 8, easy to code, cheap to evaluate, and not easy to solve. In support of the latter contention, we present test results from MINPACK AND NL2SOL