% Singular Value Plots of the perturbed pendulum models
%
[A,B,C,D] = mod_pend;
G = pck(A,B,C,D);
omega = logspace(-1,2,100);
hold off
%
[d1,d2,d3,d4,d5,d6] = ndgrid([-1 0 1],[-1 0 1],[-1 0 1], ...
                             [-1 0 1],[-1 0 1],[-1 0 1]);
for j = 1:729
    delta = diag([d1(j),d2(j),d3(j),d4(j),d5(j),d6(j)]);
    olp = starp(delta,G);
    olp_ic = sel(olp,[1:3],[1:2]);
    olp_g = vsvd(frsp(olp_ic,omega));
    figure(1)
    vplot('liv,lm',sel(olp_g,1,1),'r-', ...
          sel(olp_g,2,1),'c-')
    tmp1 = 'Singular value plots of the';
    tmp2 = ' perturbed pendulum models';
    title([tmp1 tmp2]);
    xlabel('Frequency (rad/sec)')
    hold on
end
hold off