function pentagon(z)

%
% PENTAGON(Z)
% Similarity transformation of the 5th roots of unity by 
% multiplying them by the complex number z.
%

p = [1 0 0 0 0 -1];
r=roots(p);
s=[r;r(1)];
v=s([1 2 4 5 3 1],:);
plot(v,'r',z*v,'g');
end