options.Ae = ones(1,4);  % linear equality constraint sum(x_i) = 1
options.be = 1;
options.lb = zeros(4,1); % lower bounds all zero, no upper bounds
A = [ 6, -2, -3, -4; -2, 9, 1, 2; -3, 1, -3, -3; -4, 2, -3, -1];
options.par_fobj = A;    % parameter matrix for the objective function
options.x0 = ones(4,1);  % some (infeasible) starting point
options.p_l = 1;         % moderate printing level

% Calling routine:
[x,y,fx,out] = min_fc(@f_sample_obj,@f_sample_con,options);
