It is shown that an analytical approach for setting an adequate initial value of a damping factor in the damped least-squares optimization process can also be used to estimate whether the given increments of variables are adequate together with some numerical experiments. It is clarified that the value of a damping factor should almost equal the median of a series of eigenvalues of a squared Jacobian matrix, which is evaluated by use of given increments.
© 1995 Optical Society of America
Hiroshi Matsui and Kazuo Tanaka, "Method for estimating numerical adequacy of derivative increments of variables in the damped least-squares automatic lens design problem," Appl. Opt. 34, 642-647 (1995)