function varargout = carromtable(X)
% Carrom table function
%
%   CARROMTABLE([x1, x2]) returns the value of the Carrom table
%   function at the specified points. [x1] and [x2] may be vectors. 
%   The search domain is
%
%               -10 < x_i < 10
%
%   The four global minimum are found near the corners of the interval,
%   with
%
%               fmin = 24.1568155.

% Author: Rody P.S. Oldenhuis
% Delft University of Technology
% E-mail: oldenhuis@dds.nl
% Last edited 20/Jul/2009

    % if no input is given, return dimensions, bounds and minimum
    if (nargin == 0)
        varargout{1} = 2;  % # dims
        varargout{2} = [-10, -10]; % LB
        varargout{3} = [+10, +10]; % UB
        varargout{4} = [+9.646157266348881e+000, +9.646134286497169e+000
                        -9.646157266348881e+000, +9.646134286497169e+000
                        +9.646157266348881e+000, -9.646134286497169e+000
                        -9.646157266348881e+000, -9.646134286497169e+000]; % solution
        varargout{5} = -2.415681551650653e+001; % function value at solution

    % otherwise, output function value
    else
        
        % keep values in the serach interval
        X(X < -10) = inf;     X(X > 10) = inf;
        
        % split input vector X into x1, x2
        if size(X, 1) == 2
            x1 = X(1, :);        x2 = X(2, :);
        else
            x1 = X(:, 1);        x2 = X(:, 2);
        end
        
        % output function value
        varargout{1} = -((cos(x1).*cos(x2).*exp(abs(1 - sqrt(x1.^2 + x2.^2)/pi))).^2)/30;
    
    end
     
end