Structure method for solving the nearest Euclidean distance matrix problem

A matrix with zero diagonal is called a Euclidean distance matrix when the matrix values are measurements of distances between points in a Euclidean space. Because of data errors such a matrix may not be exactly Euclidean and it is desirable in many applications to find the best Euclidean matrix which approximates the non-Euclidean matrix. In this paper the problem is formulated as a smooth unconstrained minimization problem, for which rapid convergence can be obtained. Comparative numerical results are reported.