#範例2-8：結合numpy與matplotlib的繪圖，畫出三條線(y=x,y=x^2, y=x^3)
import matplotlib.pyplot as plt
import numpy as np

# 從0～5，每隔0.01取一個點當作x
x = np.arange(0,5,0.01)

# y = x
plt.plot(x,x,'r-')

# y = x^2
plt.plot(x,x*x,'b:')

# y = x^3
plt.plot(x,x*x*x,'g--')
plt.show()