from random import choice
 
class RandomWalk():
 """一個(gè)生成隨機(jī)漫步數(shù)據(jù)的類"""
 
 def __init__(self,num_points=5000):
 """初始化隨機(jī)漫步的屬性"""
 self.num_points = num_points
 
 #所有隨機(jī)漫步都始于(0,0)
 self.x_values = [0]
 self.y_values = [0]
 
 def fill_walk(self):
 """計(jì)算隨機(jī)漫步包含的所有點(diǎn)"""
 
 #不斷漫步，直到列表達(dá)到指定的長度
 while len(self.x_values) < self.num_points:
  # 決定前進(jìn)方向以及沿這個(gè)方向前進(jìn)的距離
  x_direction = choice([1,-1])
  x_distance = choice([0,1,2,3,4])
  x_step = x_direction * x_distance
 
  y_direction = choice([1,-1])
  y_distance = choice([0,1,2,3,4])
  y_step = y_direction * x_distance
 
  # 拒絕原地踏步
  if x_step == 0 and y_step == 0:
  continue
 
  #計(jì)算下一個(gè)點(diǎn)的x和y值
  next_x = self.x_values[-1] + x_step
  next_y = self.y_values[-1] + y_step
 
  self.x_values.append(next_x)
  self.y_values.append(next_y) 

import matplotlib.pyplot as plt 
 
from random_walk import RandomWalk
 
# 創(chuàng)建一個(gè)RandomWalk實(shí)例，并將其包含的點(diǎn)都繪制出來
rw = RandomWalk(50000)
rw.fill_walk()
 
# 設(shè)置繪圖窗口的尺寸
plt.figure(dpi=80,figsize=(10,6))
 
# 設(shè)置點(diǎn)按先后順序增加顏色深度
point_numbers = list(range(rw.num_points))
plt.scatter(rw.x_values,rw.y_values,c=point_numbers,cmap=plt.cm.Blues,
 edgecolor='none',s=1)
 
# 突出起點(diǎn)和終點(diǎn)，起點(diǎn)設(shè)置為綠色，終點(diǎn)設(shè)置為紅色
plt.scatter(0,0,c='green',edgecolor='none',s=100)
plt.scatter(rw.x_values[-1],rw.y_values[-1],c='red',edgecolor='none',s=100)
 
# 隱藏坐標(biāo)軸
plt.axes().get_xaxis().set_visible(False)
plt.axes().get_yaxis().set_visible(False)
 
plt.show()