Three derivative-free projection methods for nonlinear equations with convex constraints

In this paper, we propose three derivative-free projection methods for solving nonlinear equations with convex constraints, which can be regarded as the combinations of some recently developed conjugate gradient methods and the well-known projection method. Compared with the existing derivative-free projection methods, we use some new hyperplanes to obtain the new iterate, and without the requirement of the Lipschitz continuity of the equation, we prove three new methods are globally convergent with an Armijo-type line search. Preliminary numerical results are reported to show the efficiency of the proposed methods. © 2014, Korean Society for Computational and Applied Mathematics.