% Easom's function L. LAURENT -- 15/11/2016 -- luc.laurent@lecnam.net
0001 %% Easom's function 0002 %L. LAURENT -- 15/11/2016 -- luc.laurent@lecnam.net 0003 0004 % sources available here: 0005 % https://bitbucket.org/luclaurent/optigtest/ 0006 % https://github.com/luclaurent/optigtest/ 0007 0008 % optiGTest - set of testing functions A toolbox to easy manipulate functions. 0009 % Copyright (C) 2017 Luc LAURENT <luc.laurent@lecnam.net> 0010 % 0011 % This program is free software: you can redistribute it and/or modify 0012 % it under the terms of the GNU General Public License as published by 0013 % the Free Software Foundation, either version 3 of the License, or 0014 % (at your option) any later version. 0015 % 0016 % This program is distributed in the hope that it will be useful, 0017 % but WITHOUT ANY WARRANTY; without even the implied warranty of 0018 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 0019 % GNU General Public License for more details. 0020 % 0021 % You should have received a copy of the GNU General Public License 0022 % along with this program. If not, see <http://www.gnu.org/licenses/>. 0023 0024 % 0025 %4 global minimas : f(x1,x2)=-1 for (pi,pi) 0026 % 0027 %Design space: -100<xi<100 0028 0029 0030 function [p,dp]=funEasom(xx) 0031 0032 %constants 0033 a=pi; 0034 0035 %variables 0036 xxx=xx(:,:,1); 0037 yyy=xx(:,:,2); 0038 0039 %evaluation and derivatives 0040 cx=cos(xxx); 0041 cy=cos(yyy); 0042 xp=xxx-a; 0043 yp=yyy-a; 0044 exy=exp(-xp.^2-yp.^2); 0045 p=-cx.*cy.*exy; 0046 % 0047 if nargout==2 0048 sx=sin(xxx); 0049 sy=sin(yyy); 0050 % 0051 dp(:,:,1)=exy.*(sx.*cy+2*xp.*cx.*cy); 0052 dp(:,:,2)=exy.*(sy.*cx+2*yp.*cx.*cy); 0053 end 0054 end