# hopf bifurcation
dx/dt = -p*x+y-x*y^2
dy/dt = -x-p*y-y^3
x(0)=1
y(0)=1
param p=1
@ total=150,dt=.05,xlo=-5,xhi=5, ylo=-1, yhi=1, xp=x, yp=y
done