from pylab import *
Dt = 0.01
def initialize():
global x, xresult, y, yresult
x = y = 0.1
xresult = [x]
yresult = [y]
def observe():
global x, xresult, y, yresult
xresult.append(x)
yresult.append(y)
def initialize():
global x, xresult, y, yresult
x = y = 0.1
xresult = [x]
yresult = [y]
def observe():
global x, xresult, y, yresult
xresult.append(x)
yresult.append(y)
def update():
global x, xresult, y, yresult
nextx= x + y*Dt
nexty= y + (-r*(x**2 - 1)* y - x)*Dt
x, y = nextx, nexty
def plot_phase_space():
initialize()
for t in range(10000):
update()
observe()
plot (xresult, yresult)
axis ('image')
axis([-3, 3, -3, 3])
title('r = ' + str(r))
rs = [- 1, - 0.1, 0, 0.1, 1]
for i in range(len(rs)):
subplot(1, len (rs), i + 1 )
r = rs[i]
plot_phase_space()
show ()Credits: MathLibreText