#極座標作圖

import numpy as np
import matplotlib.pyplot as plt

t = np.linspace(-20,20,500)
r=np.sin(8*t/5)
x = r*np.cos(t)
y= r*np.sin(t)

plt.figure(figsize=(5,5),dpi=80)
plt.plot(x,y,color="blue",linewidth=2)
plt.show()