You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: minbrack.m
    path of file: ./repos/bnt/netlab3.3
    
    the code of the file until where you have to start completion: function  [br_min, br_mid, br_max, num_evals] = minbrack(f, a, b, fa,  ...
			 varargin)
%MINBRACK Bracket a minimum of a function of one variable.
%
%	Description
%	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
%
%	See also
%	LINEMIN, LINEF
%

%	Copyright (c) Ian T Nabney (1996-2001)

% Check function string
f = fcnchk(f, length(varargin));

    
function  [br_min, br_mid, br_max, num_evals] = minbrack(f, a, b, fa,  ...
			 varargin)
%MINBRACK Bracket a minimum of a function of one variable.
%
%	Description
%	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
%
%	See also
%	LINEMIN, LINEF
%

%	Copyright (c) Ian T Nabney (1996-2001)

% Check function string
f = fcnchk(f, length(varargin));

% Value of golden section (1 + sqrt(5))/2.0
phi = 1.6180339887499;

% Initialise count of number of function evaluations
num_evals = 0;

% A small non-zero number to avoid dividing by zero in quadratic interpolation
TINY = 1.e-10;

% Maximal proportional step to take: don't want to make this too big
% as then spend