Matplotlib.axes.Axes.twinx() in Python

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Matplotlib is a library in Python and it is numerical – mathematical extension for NumPy library. The Axes Class contains most of the figure elements: Axis, Tick, Line2D, Text, Polygon, etc., and sets the coordinate system. And the instances of Axes supports callbacks through a callbacks attribute.

matplotlib.axes.Axes.twinx() Function

The Axes.twinx() function in axes module of matplotlib library is used to create a twin Axes sharing the xaxis.

Syntax: Axes.twinx(self)

Parameters: This method does not accepts any parameters.

Return value: This method is used to returns the following.

ax_twin : This returns the newly created Axes instance.

Below examples illustrate the matplotlib.axes.Axes.twinx() function in matplotlib.axes:

Example 1:

# Implementation of matplotlib function 
import matplotlib.pyplot as plt 
import numpy as np 
  
  
def GFG1(temp): 
    return (5. / 9.) * (temp - 32) 
  
def GFG2(ax1): 
    y1, y2 = ax1.get_ylim() 
    ax_twin .set_ylim(GFG1(y1), GFG1(y2)) 
    ax_twin .figure.canvas.draw() 
  
fig, ax1 = plt.subplots() 
ax_twin = ax1.twinx() 
  
ax1.callbacks.connect("ylim_changed", GFG2) 
ax1.plot(np.linspace(-40, 120, 100)) 
ax1.set_xlim(0, 100) 
  
ax1.set_ylabel('Fahrenheit') 
ax_twin .set_ylabel('Celsius') 
  
fig.suptitle('matplotlib.axes.Axes.twinx()\ 
 function Example\n\n', fontweight ="bold") 
  
plt.show() 

Output:

Example 2:

# Implementation of matplotlib function 
import numpy as np 
import matplotlib.pyplot as plt 
  
# Create some mock data 
t = np.arange(0.01, 10.0, 0.001) 
data1 = np.exp(t) 
data2 = np.sin(0.4 * np.pi * t) 
  
fig, ax1 = plt.subplots() 
  
color = 'tab:blue'
ax1.set_xlabel('time (s)') 
ax1.set_ylabel('exp', color = color) 
ax1.plot(t, data1, color = color) 
ax1.tick_params(axis ='y', labelcolor = color) 
  
ax2 = ax1.twinx() 
  
color = 'tab:green'
ax2.set_ylabel('sin', color = color) 
ax2.plot(t, data2, color = color) 
ax2.tick_params(axis ='y', labelcolor = color) 
  
fig.suptitle('matplotlib.axes.Axes.twinx() \ 
function Example\n\n', fontweight ="bold") 
  
plt.show() 