# 利用隨機亂數作 1/4 的圓

import numpy as np
import matplotlib.pyplot as plt
import random

plt.figure(figsize=(5,5),dpi=80)

ax = plt.gca()  # gca stands for 'get current axis'
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')
ax.xaxis.set_ticks_position('bottom')
ax.spines['bottom'].set_position(('data',0))
ax.yaxis.set_ticks_position('left')
ax.spines['left'].set_position(('data',0))
 
X=[]
Y=[]
n=100000
for i in range(1,n+1,1):
    x=random.random()         
    y=random.random()
    if x*x+y*y<= 1.0 :
        X.append(x)
        Y.append(y)

plt.scatter(X,Y)

plt.show()