Abstract.The key idea of the material presented in the paper is that all commonly used variable metric updates consist of the projection part that nullifies vector parallel to differences of the derivatives of the minimized function and the second one (the same for all known formulae) ensuring verification of the quasi-Newton condition at each step of the method.

In the paper a new class of updates ensuring inheritance of the conjugacy property (when applied to a strictly convex QP problem with exact directional minimization) is introduced. Its properties are analysed and some preliminary computational results on some test problems suggested by Moré [#! more!#] are reported.

Received: August 14, 2007

AMS Subject Classification: 65K05, 90C53

Key Words and Phrases: variable metric methods, affine projections, conjugacy property

Source: International Journal of Pure and Applied Mathematics
ISSN: 1311-8080
Year: 2009
Volume: 52
Issue: 4