function value = gp(x) %---------------------------------------------------------- % Goldstein-Price Test Function for Nonlinear Optimization % % Taken from "Towards Global Optimisation 2",edited by L.C.W. Dixon and G.P. % Szego, North-Holland Publishing Company, 1978. ISBN 0 444 85171 2 % % -2 <= x1 <= 2 % -2 <= x2 <= 2 % fmin = 3 % xmin = 0 % -1 %---------------------------------------------------------- %---------------------------------------------------------% % http://www4.ncsu.edu/~definkel/research/index.html %---------------------------------------------------------% x1 = x(1); x2 = x(2); value =(1+(x1+x2+1).^2.*(19-14.*x1+3.*x1.^2-14.*x2+6.*x1.*x2+3.*x2.^2))... .*(30+(2.*x1-3.*x2).^2.*(18-32.*x1+12.*x1.^2+48.*x2-36.*x1.*x2+27.*x2.^2));