无标题文章

import pylab as py

class phase_space:

def __init__(self,r):

self.x=[1]

self.y=[0]

self.z=[0]

self.vx=[0]

self.vy=[0]

self.vz=[0]

self.t=[0]

self.dt=0.0001

self.sigma=10

self.b=8/3

self.r=r

self.xn=[]

self.yn=[]

self.zn=[]

def calculate1(self):

for i in range(5000000):

self.vx.append(self.sigma*(self.y[-1]-self.x[-1]))

self.vy.append(-self.x[-1]*self.z[-1]+self.r*self.x[-1]-self.y[-1])

self.vz.append(self.x[-1]*self.y[-1]-self.b*self.z[-1])

self.x.append(self.x[-1]+self.vx[-1]*self.dt)

self.y.append(self.y[-1]+self.vy[-1]*self.dt)

self.z.append(self.z[-1]+self.vz[-1]*self.dt)

self.t.append(self.t[-1]+self.dt)

if self.t[-1]>30:

if abs(self.x[-1])<0.01:

self.yn.append(self.y[-1])

self.zn.append(self.z[-1])

return self.yn,self.zn

def calculate2(self):

for i in range(5000000):

self.vx.append(self.sigma*(self.y[-1]-self.x[-1]))

self.vy.append(-self.x[-1]*self.z[-1]+self.r*self.x[-1]-self.y[-1])

self.vz.append(self.x[-1]*self.y[-1]-self.b*self.z[-1])

self.x.append(self.x[-1]+self.vx[-1]*self.dt)

self.y.append(self.y[-1]+self.vy[-1]*self.dt)

self.z.append(self.z[-1]+self.vz[-1]*self.dt)

self.t.append(self.t[-1]+self.dt)

if self.t[-1]>30:

if abs(self.y[-1])<0.01:

self.xn.append(self.x[-1])

self.zn.append(self.z[-1])

return self.yn,self.xn

sub1=py.subplot(211)

A=phase_space(25)

A.calculate1()

sub1.plot(A.yn,A.zn,'k.')

sub1.set_title('When x=0')

py.xlabel('y')

py.ylabel('z')

sub2=py.subplot(212)

A=phase_space(25)

A.calculate2()

sub2.plot(A.xn,A.zn,'k.')

sub1.set_title('When y=0')

py.xlabel('x')

py.ylabel('z')