allee.py

import scipy.integrate
import numpy as np
import matplotlib.pyplot as plt

def allee(x,t,r,a,k):
    return r*x*(x-a)*(1.0 - x/k)



x0 = 18
r = 0.03
a = 20.0
k = 100.0
time = np.linspace(0,50,10000)
traject = scipy.integrate.odeint(allee, x0 ,time, args=(r,a,k,))


x0 = 22
time2 = np.linspace(0,50,10000)
traject2 = scipy.integrate.odeint(allee, x0 ,time2, args=(r,a,k,))

x0 = 120
time3 = np.linspace(0,50,10000)
traject3 = scipy.integrate.odeint(allee, x0 ,time3, args=(r,a,k,))



plt.plot(time, traject, '-r')
plt.plot(time2, traject2, '-b')
plt.plot(time3, traject3, '-y')
plt.show()