Improvement of convergence of an iterative method for finding polynomial factors of analytic functions

In this paper, we consider an iterative method for evaluating the coefficients of a monic factor of an analytic function using complex circular arithmetic. In a previous paper, the authors presented a factoring method that finds a cluster of zeros as a polynomial factor. We analyze the convergence behavior of this method and discuss a technique for improving convergence. Numerical examples illustrate the aspects of the improved method.