function [fvec,J] = box(n,m,x,opt)% *****************************************************************% *****************************************************************% Function [fvec,J] = box(n,m,x,opt)% Box three-dimensional function      [12]% Dimensions:   n=3     m=10% Function definition:%       f(x)= exp[-t(i)x1]-exp[-t(i)x2]-x3[exp[-t(i)]-exp[-10t(i)]]%       where t(i)=(0.1)i% Standard Starting Points: (0,10,20)% Minima of f=0 at (1,10,1), (10,1,-1) and wherever x1=x2 and x3-0% ******************************************************************for i = 1:m  t(i) = .1*i;       if((opt ==1) | (opt==3))     fvec(i) =  exp(-t(i)*x(1))-exp(-t(i)*x(2))-x(3)*(exp(-t(i))-exp(-10*t(i)));  end;  if((opt ==2) | (opt ==3))     J(i,1)  =  -t(i)*exp(-t(i)*x(1));     J(i,2)  =  t(i)*exp(-t(i)*x(2));     J(i,3)  = -(exp(-t(i))-exp(-10*t(i)));  end;end;fvec=fvec';if((opt<1)|(opt>3))        disp('Error: Option value sent to  BOX.M is either <1 or >3');end;