1. ASYMPTOTIC CONVERGENCE ANALYSIS OF A NEW CLASS OF PROXIMAL POINT METHODS.
- Author
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Hager, William W. and Hongchao Zhang
- Subjects
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STOCHASTIC convergence , *NONLINEAR functional analysis , *HILBERT space , *BANACH spaces , *INNER product spaces , *INVARIANT subspaces , *VECTOR spaces , *INDEFINITE inner product spaces , *MATHEMATICAL analysis - Abstract
Finite dimensional local convergence results for self-adaptive proximal point methods and nonlinear functions with multiple minimizers are generalized and extended to a Hilbert space setting. The principle assumption is a local error bound condition which relates the growth in the function to the distance to the set of minimizers. A local convergence result is established for almost exact iterates. Less restrictive acceptance criteria for the proximal iterates are also analyzed. These criteria are expressed in terms of a subdifferential of the proximal function and either a subdifferential of the original function or an iteration difference. If the proximal regularization parameter μ(x) is sufficiently small and bounded away from zero and f is sufficiently smooth, then there is local linear convergence to the set of minimizers. For a locally convex function, a convergence result similar to that for almost exact iterates is established. For a locally convex solution set and smooth functions, it is shown that if the proximal regularization parameter has the form μ(x) = β∥f′[x]∥η, where η ϵ (0, 2), then the convergence is at least superlinear if η ϵ (0, 1) and at least quadratic if η [1, 2). [ABSTRACT FROM AUTHOR]
- Published
- 2007
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