In this paper, low-order Newton methods are proposed that make use of
previously obtained second-derivative information by suitable precondi
tioning. When applied to a particular 2-dimensional Newton method (the
LS method), it is shown that a member of the Broyden family of quasi-
Newton methods is obtained. Algorithms based on this preconditioned LS
model are tested against some variations of the BFGS method and shown
to be much superior in terms of number of iterations and function eva
luations, but not so effective in terms of number of gradient evaluati
ons.