AAS 97-138

A NEW LOOK AT THE PROBLEM OF CONSTRAINTS VIOLATION

S. Djerassi, Haifa, Israel K. W. Buffinton, Bucknell University

Abstract

The present work deals with the problem of constraints violation associated with numerical integration of ordinary differential equations subject to constraints. A new method is set forth for the elimination of constraints violation. The method involves the definition of 'old' constraints and 'new' constraints, the removal of the 'old' constraints and the imposition of the 'new' constraints, and the evaluation, at each integration step, of changes in the integration variables resulting from the removal-imposition process. The method is shown to be superior to the classical Baumgarte procedure for constraints violation elimination.