% Copyright (C) 2003 Andy Adler
% 
% This program is free software; you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation; either version 2 of the License, or
% (at your option) any later version.
% 
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
% GNU General Public License for more details.
% 
% You should have received a copy of the GNU General Public License
% along with this program; if not, write to the Free Software
% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

% -*- texinfo -*-
% @deftypefn {Function File} {[@var{x}] =} fmins(@var{f},@var{X0},@var{options},@var{grad},@var{P1},@var{P2}, ...)
% 
% Find the minimum of a funtion of several variables.
% By default the method used is the Nelder&Mead Simplex algorithm
%
% Example usage:
%   fmins(inline('(x(1)-5).^2+(x(2)-8).^4'),[0;0])
% 
% @strong{Inputs}
% @table @var 
% @item f 
% A string containing the name of the function to minimize
% @item X0
% A vector of initial parameters fo the function @var{f}.
% @item options
% Vector with control parameters (not all parameters are used)
% @verbatim
% options(1) - Show progress (if 1, default is 0, no progress)
% options(2) - Relative size of simplex (default 1e-3)
% options(6) - Optimization algorithm
%    if options(6)==0 - Nelder & Mead simplex (default)
%    if options(6)==1 - Multidirectional search Method
%    if options(6)==2 - Alternating Directions search
% options(5)
%    if options(6)==0 && options(5)==0 - regular simplex
%    if options(6)==0 && options(5)==1 - right-angled simplex
%       Comment: the default is set to "right-angled simplex".
%         this works better for me on a broad range of problems,
%         although the default in nmsmax is "regular simplex"
% options(10) - Maximum number of function evaluations
% @end verbatim
% @item grad
% Unused (For compatibility with Matlab)
% @item P1,P2, ...
% Optional parameters for function @var{f} 
%
% @end table
% @end deftypefn

function ret=fmins(funfun, X0, options, grad, varargin)
    stopit = [1e-3, inf, inf, 1, 0, -1];
    minfun = 'nmsmax'; 

    if nargin<=3; options=[]; end

    if length(options)>=1; stopit(5)= options(1); end
    if length(options)>=2; stopit(1)= options(2); end
    if length(options)>=5;
        if     options(6)==0; minfun= 'nmsmax'; 
            if     options(5)==0; stopit(4)= 0;
            elseif options(5)==1; stopit(4)= 1;
            else   error('options(5): no associated simple strategy');
            end
        elseif options(6)==1; minfun= 'mdsmax';
        elseif options(6)==2; minfun= 'adsmax';
        else   error('options(6) does not correspond to known algorithm');
        end
    end
    if length(options)>=10; stopit(2)= options(10); end

    ret = feval(minfun, funfun,  X0, stopit, [], varargin{:});