%polynomial version of logistic cubed. Computes fixed points 
%and derivative at them
r=input('r=')
p=[-r r 0];
q=-r*conv(p,p) +[0 0 r*p];
P=-r*conv(q,q)+[0 0 0 0 r*q];
X=[0 0 0 0 0 0 0 1 0];
Q=polyder(P);
z=roots(P-X);
w=[z, polyval(Q,z)]
