3_x、y轴设置到原点、x=-1的画法

from numpy import *
import matplotlib.pyplot as plt

x = linspace(-5, 5)
x3 = linspace(-1, -1)
y3 = linspace(-10, 10)
y1 = x * 2
y2 = x ** 2 + 1
plt.xlim(-5, 5)
plt.ylim(-10, 10)
ax = plt.gca()
ax.spines['top'].set_color('none')
ax.spines['right'].set_color('none')
ax.spines['bottom'].set_position(('data', 0))
ax.spines['left'].set_position(('data', 0))
# plt.figure(num=6,)
plt.plot(x, y1 + y2, 'purple', linewidth='1.0')
plt.plot(x3, y3, linestyle='--')
plt.show()

通过设置上边框，右边框的'data'值为0

ax = plt.gca()  # gca =get current axis 整个figure系统
ax.spines['top'].set_position(('data',0))
ax.spines['right'].set_position(('data',0))

 

 

 

将左面与下面的边框设置为none，隐藏起来，但是发现刻度孤零零的
ax.spines['left'].set_color('none')
ax.spines['bottom'].set_color('none')

 

 改进：

ax = plt.gca()
ax.spines['top'].set_color('none')
ax.spines['right'].set_color('none')
ax.spines['bottom'].set_position(('data',0))
ax.spines['left'].set_position(('data',0))