Barrier methods for constrained optimization, widely applied in the 19
60s and 1970s, have recently enjoyed a revival of popularity. A line s
earch with respect to a logarithmic barrier function or related potent
ial function is often part of modern interior methods. Standard line s
earch procedures tend to be inefficient in this context for two reason
s: an inappropriate choice of initial trial step if any constraints ar
e nonlinear, and poor approximation of the barrier function by low-ord
er polynomial interpolants. This paper discusses line search strategie
s specifically designed for the logarithmic barrier function.