1D Random Walks with Python

By: Tao Steven Zheng (郑涛)

import numpy as np
import matplotlib.pyplot as plt

 def Randwalk(n):
 
    x = 0
    y = 0
 
    time = [x]
    position = [y] 
 
    for i in range (1,n+1):
        move = np.random.uniform(0,1)
 
        if move < 0.5:    
            x += 1
            y += 1  
 
        if move > 0.5:    
            x += 1
            y += -1
  
        time.append(x)
        position.append(y)
 
    return [time,position]


'''Trials and plots'''
 Randwalk1 = Randwalk(1000)
 Randwalk2 = Randwalk(1000)
 Randwalk3 = Randwalk(1000)
 plt.plot(Randwalk1[0],Randwalk1[1],'r-', label = "Randwalk1")
 plt.plot(Randwalk2[0],Randwalk2[1],'g-', label = "Randwalk2")
 plt.plot(Randwalk3[0],Randwalk3[1],'b-', label = "Randwalk3")
 plt.title("1-D Random Walks")
 plt.legend(loc='upper center', bbox_to_anchor=(0.5,-0.1), fancybox=True, shadow=True)
 plt.show()