圖形，即與y軸交叉

Question

如何使用matplotlib繪製這樣的圖形？

Answer 1

檢查this example從this group

例如：

from matplotlib import pyplot as plt 
import numpy as np 

def line(x, slope=1, zero=0): 
    return zero + slope * x 

x = np.array([-4,10]) 
y1 = line(x, 2, 2) 
y2 = line(x, 1, 3) 

fig = plt.figure() 
ax = fig.add_subplot(111) 
ax.plot(x,y1) 
ax.plot(x,y2) 

ax.spines['left'].set_position(('data', 0)) 
ax.spines['right'].set_color('none') 
ax.spines['bottom'].set_position(('data',0)) 
ax.spines['top'].set_color('none') 
ax.spines['left'].set_smart_bounds(True) 
ax.spines['bottom'].set_smart_bounds(True) 
ax.xaxis.set_ticks_position('bottom') 
ax.yaxis.set_ticks_position('left') 

plt.show() 

或接近的圖片（這裏我消除set_smart_bounds因爲在Win7似乎沒有效果例如）：

ax.spines['left'].set_position(('data', 0)) 
ax.spines['right'].set_color('none') 
ax.spines['bottom'].set_position(('data',0)) 
ax.spines['top'].set_color('none') 
ax.xaxis.set_ticks_position('bottom') 
ax.yaxis.set_ticks_position('left') 
plt.ylim(ymin=0) 
plt.show()