python plt可视化——打印特殊符号和制作图例代码

import matplotlib.pyplot as plt

x = [i+1 for i in range(20)]
y = x
plt.figure()
plt.title(r'$\alpha$ > $\beta$') # 打印α>β
plt.xlabel(r'$\theta$') # 打印θ
plt.ylabel(r'$\omega$') # 打印ω
plt.plot(x, y)
plt.show()

import matplotlib.pyplot as plt

x = [i+1 for i in range(20)]
y = x
plt.figure()
plt.title(r'$\alpha_i$ > $\beta_i$') # 打印α_i > β_i
plt.xlabel(r'$\theta^2$') # 打印θ^2
plt.ylabel(r'$\omega^n$') # 打印ω^n
plt.plot(x, y)
plt.show()

import matplotlib.pyplot as plt
from math import sin, cos, exp

x = [(i+1)/100 for i in range(1000)]
y1 = [sin(i) for i in x]
y2 = [cos(i) for i in x]
y3 = [exp(-i) for i in x]

plt.figure()
plt.plot(x, y1)
plt.plot(x, y2)
plt.plot(x, y3)

# 分别对应y1，y2，y3标志图例，注意e^(-x)要加大括号表示(-x)是一个整体，都是上标
plt.legend(['sin(x)', 'cos(x)', '$e^{-x}$'])
plt.show()

>>>print("I like %s and can eat %.2f kg." % ("orange", 1.5))
 
I like orange and can eat 1.50 kg.
 
>>>pi = 3.1415926
>>>print("pi = %.*f" % (5, pi))
 
pi = 3.14159