function main(); // Main function for iteration of static values in // eigenvalue problem // // // Grundlagen der Modellierung und Simulation // WiSe 2012/13 //%%%%%%%%%%%%%%%%%%%%%% Start Values %%%%%%%%%%%%%%%%%%%% x = [-3; 0; 0] //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% x_fixpunkt = x; x_newton = x; x_qnewton = x; //%%%%%%%%%%%%%%%%%%% Fixpunkt %%%%%%%%%%%%%%%%%%%%%%%%%%% [it_f, x_f] = fixpoint(x_fixpunkt); //%%%%%%%%%%%%%%%%%%% Newton %%%%%%%%%%%%%%%%%%%%%%%%%%%%% [it_n, x_n] = newton(x_newton); //%%%%%%%%%%%%%%%%%%% Quasi-Newton %%%%%%%%%%%%%%%%%%%%%%%%%%%%% [it_qn, x_qn] = quasi_newton(x_qnewton); //%%%%%%%%%%%%%%%%%%% Output %%%%%%%%%%%%%%%%%%%%%%%%%%%%% disp('Startwert x'); x disp('Anzahl Iterationen bei Fixpunkt:'); it_f disp('Loesung:'); x_f(:,it_f) %x_f disp('Anzahl Iterationen bei Newton:'); it_n disp('Loesung:'); x_n(:,it_n) %x_n disp('Anzahl Iterationen bei Quasi-Newton:'); it_qn disp('Loesung:'); x_qn(:,it_qn) semilogy(1:it_n, abs(x_n(3,:)-2), ... 1:it_f, abs(x_f(3,:)-2), ... 1:it_qn, abs(x_qn(3,:)-2)) title('Iterationsverfahren'); legend('error (Newton) ','error (FixP)','error (Quasi-Newton)') xlabel('Anzahl Iterationen'); ylabel('Fehler in lambda'); endfunction