function [f,g] = obj3a(x);

%Anzahl der Punkte im Federsystem
N=length(x)/2;

%Gewichte als Parameter - globale Variable
global w;

%Federkonstante als Parameter - globale Variable
global K;

%Abstand zwischen 2 Federn
Li=1./(N+1);

%Auslenkung
dLi = sqrt(([0;x(1:N)]-[x(1:N);1]).^2+([0;x(N+1:2*N)]-[x(N+1:2*N);0]).^2)-Li;

%Zielfunktional, Formel (1.13)
f = 0.5*sum(K.*(dLi.^2)) + sum(w.*x(N+1:2*N));

%Gradient 
g=zeros(size(x));
g=g+[zeros(N,1);w];

if (N > 1)
 g(1)=g(1)+(K(1)*dLi(1))/(Li+dLi(1))*x(1)+(K(2)*dLi(2))/(Li+dLi(2))*(x(1)-x(2));
 g(N+1)=g(N+1)+(K(1)*dLi(1))/(Li+dLi(1))*x(N+1)+(K(2)*dLi(2))/(Li+dLi(2))*(x(N+1)-x(N+2));
 g(N)=g(N)+(K(N)*dLi(N))/(Li+dLi(N))*(x(N)-x(N-1))+(K(N+1)*dLi(N+1))/(Li+dLi(N+1))*(x(N)-1.);
 g(2*N)=g(2*N)+(K(N)*dLi(N))/(Li+dLi(N))*(x(2*N)-x(2*N-1))+(K(N+1)*dLi(N+1))/(Li+dLi(N+1))*(x(2*N));
 for j=2:N-1
  g(j)=g(j)+(K(j)*dLi(j))/(Li+dLi(j))*(x(j)-x(j-1))+(K(j+1)*dLi(j+1))/(Li+dLi(j+1))*(x(j)-x(j+1));
  g(N+j)=g(N+j)+(K(j)*dLi(j))/(Li+dLi(j))*(x(N+j)-x(N+j-1))+(K(j+1)*dLi(j+1))/(Li+dLi(j+1))*(x(N+j)-x(N+j+1));
 end;
else 
 g(1) = g(1)+(K(1)*dLi(1))/(Li+dLi(1))*x(1)+(K(2)*dLi(2))/(Li+dLi(2))*(x(1)-1.);
 g(2) = g(2)+(K(1)*dLi(1))/(Li+dLi(1))*x(2)+(K(2)*dLi(2))/(Li+dLi(2))*(x(2));
end;