unc_nn_schwefel.m

matlab最优化理论的实现

function [fval]=unc_nn_Schwefel(x)
%reference:
%note that you can get the formulation of unc_nn_Schwefel from some
%aritcles,such as
%(1)Hartmut Pohlheim 'Genetic Algorithm Toolbox Test Functions'
%
%algorithm:
%below code is  edited according to 
%(1)Hartmut Pohlheim 'Genetic Algorithm Toolbox Test Functions'
%
%solution:
% where the bounds are -500<=x<=500;
%The global minimum is at x*=420.9687*ones(n,1),and f(x*)=-n*418.9829;
% Schwefel's function is deceptive in that the global minimum is geometricaly distant, over
% the parameter space, from the next best local minima. Therefore, the search algorithms
% are potentially prone to convergence in the wrong direction.

%Copyright:
% programmers:oiltowater.
% It comply with the GPL2.0
% Copyright 2006  oiltowater 


fval=sum(-x.*sin(sqrt(abs(x))));