function G=ps41a_6242_2004(s)
% function G=ps41a_6242_2004(s)
% 
% construct an LTI system with singular numbers s(i)
% s(i) must be a column of non-repeated positive numbers

s=s(:);                         % make sure s is a column
n=length(s);                    % system order
B=ones(n,1);                    % the column of ones
A=repmat(-1,n,n)./(s*B'+B*s');  % solving analytically for A
disp(['Stability margin: ' num2str(max(real(eig(A))))])
G=ss(A,B,B',0);                 % resulting system