kwea123

stena

# -*- coding: cp1252 -*-

# Minimize a continuous differentialble multivariate function. Starting point
# is given by "X" (D by 1), and the function named in the string "f", must
# return a function value and a vector of partial derivatives. The Polack-
# Ribiere flavour of conjugate gradients is used to compute search directions,
# and a line search using quadratic and cubic polynomial approximations and the
# Wolfe-Powell stopping criteria is used together with the slope ratio method
# for guessing initial step sizes. Additionally a bunch of checks are made to
# make sure that exploration is taking place and that extrapolation will not