brmin, brmid, brmax, numevals] = minbrack(f, a, b, fa)
finds a bracket of three points around a local minimum of
f. The function f must have a one dimensional domain.
a < b is an initial guess at the minimum and maximum points
of a bracket, but minbrack will search outside this interval if
necessary. The bracket consists of three points (in increasing order)
such that f(brmid) < f(brmin) and f(brmid) < f(brmax).
fa is the value of the function at a: it is included to
avoid unnecessary function evaluations in the optimization routines.
The return value numevals is the number of function evaluations
in minbrack.
minbrack(f, a, b, fa, p1, p2, ...) allows additional
arguments to be passed to f
f in the direction sd can be found in linemin
[min, mid, max, nevals]] = minbrack('linef', 0.0, 1.0, fa, f, pt, dir);
where the function linef is used to turn a general function f
into a one dimensional one.
linemin, linefCopyright (c) Ian T Nabney (1996-9)