>> m = 1; >> c = 1; >> b = 0.5; >> M = [1, 0; 0, 1]*m; >> B = [2, -1; -1, 3]*b; >> C = [2, -1; -1, 2]*c;
>> [X, E] = polyeig(C, B, M) X = 0.5713 - 0.2867i 0.5713 + 0.2867i 0.5156 + 0.5047i 0.5156 - 0.5047i -0.7687 + 0.0232i -0.7687 - 0.0232i 0.6066 + 0.3339i 0.6066 - 0.3339i E = -0.8708 + 1.4606i -0.8708 - 1.4606i -0.3792 + 0.9453i -0.3792 - 0.9453i
>> la = E([3, 1]) >> Phi = X(:, [3, 1]) la = -0.3792 + 0.9453i -0.8708 + 1.4606i Phi = 0.5156 + 0.5047i 0.5713 - 0.2867i 0.6066 + 0.3339i -0.7687 + 0.0232i
>> nn = diag(1./Phi(1,:)); >> Phi = Phi*nn Phi = 1.0000 1.0000 0.9245 - 0.2575i -1.0912 - 0.5069i
>> delta = -real(la) >> omega = imag(la) >> r = abs(Phi) >> phi = angle(Phi) delta = 0.3792 0.8708 omega = 0.9453 1.4606 r = 1.0000 1.0000 0.9597 1.2032 phi = 0 0 -0.2716 -2.7067
>> t = 0:0.01:10; >> >> % 1. Eigenschwingung >> j = 1; >> rj = r(:,j); >> phij = phi(:,j); >> delj = delta(j); >> omj = omega(j); >> x11 = rj(1)*exp(-delj*t).*cos(omj*t + phij(1)); >> x12 = rj(2)*exp(-delj*t).*cos(omj*t + phij(2)); >> >> % 2. Eigenschwingung >> j = 2; >> rj = r(:,j); >> phij = phi(:,j); >> delj = delta(j); >> omj = omega(j); >> x21 = rj(1)*exp(-delj*t).*cos(omj*t + phij(1)); >> x22 = rj(2)*exp(-delj*t).*cos(omj*t + phij(2)); >> >> subplot(2,1,1); >> plot(t, x11, t, x12, t, 0*t, 'k'); >> legend('x_1(t)', 'x_2(t)', 'Location', 'Best'); >> title('1. Eigenschwingung') >> >> subplot(2,1,2); >> plot(t, x21, t, x22, t, 0*t, 'k'); >> legend('x_1(t)', 'x_2(t)', 'Location', 'Best'); >> title('2. Eigenschwingung')