matplotlib

import matplotlib.pyplot as plt
import numpy as np

x = np.linspace(-1, 1, num=10)#-1到1 10個元素
y = 3 * x + 2
plt.plot(x, y) #畫圖
plt.show()  #顯示

 

x1 = np.linspace(1, 10) #默認生成元素爲50的等差數列
x2 = np.linspace(1, 10, num=5, retstep = True)
print(x1)
print(x2)
print("length of x1 is %d" %len(x1))
print("length of x2 is %d" %len(x2))

[ 1.          1.18367347  1.36734694  1.55102041  1.73469388  1.91836735
  2.10204082  2.28571429  2.46938776  2.65306122  2.83673469  3.02040816
  3.20408163  3.3877551   3.57142857  3.75510204  3.93877551  4.12244898
  4.30612245  4.48979592  4.67346939  4.85714286  5.04081633  5.2244898
  5.40816327  5.59183673  5.7755102   5.95918367  6.14285714  6.32653061
  6.51020408  6.69387755  6.87755102  7.06122449  7.24489796  7.42857143
  7.6122449   7.79591837  7.97959184  8.16326531  8.34693878  8.53061224
  8.71428571  8.89795918  9.08163265  9.26530612  9.44897959  9.63265306
  9.81632653 10.        ]
(array([ 1.  ,  3.25,  5.5 ,  7.75, 10.  ]), 2.25)
length of x1 is 50
length of x2 is 2

import matplotlib.pyplot as plt
import numpy as np

x = np.linspace(-5,5,num=100)
y1 = 2*x + 1
y2 = x**2

plt.figure(num=1,figsize=(16,9)) #第一個窗口
plt.plot(x,y1)

plt.figure(num=2)#第二個窗口
plt.plot(x,y2)

plt.figure(num=3)
plt.plot(x,y1)
plt.plot(x,y2,color='red',linewidth=1.0,linestyle='--')
plt.show()