# Matplotlib Twin Axes

In this tutorial, we will cover the concept of **twin/dual axes **in matplotlib.

In the axes class, there are many **figure elements** present like **Axis**, **Tick**, **Line2D**, **Text**, **Polygon**, etc., which are used to set the coordinate system.

When we say **twin axes**, it means a figure can have **dual x or y-axes**. Also, when plotting curves with **different units** together, then also twin axes is very useful.

In Matplotlib this task is supported with the `twinx`

and `twiny`

functions.

## Matplotlib `twinx()`

and `twiny()`

Function

In the Axes Module, there is a function named `Axes.twinx()`

function which is used to create a twin Axes that are sharing the x-axis. Similarly, the function `twiny()`

is used to create a second x axis in your figure, which means twin axes sharing the y-axis.

The syntax to use this function is as follows:

```
# for x axis
Axes.twinx(self)
# for y axis
Axes.twiny(self)
```

__ Note:__ This function

**does not take any parameters**, if you will do so then it will raise errors.

The **values returned** by this method are as follows:

**ax_twin: **which indicates that it will return the newly created Axes instance.

Now it's time to dive into some examples using this function,

## Example 1:

Here is an example of twin axes plot in matplotlib:

```
import numpy as np
import matplotlib.pyplot as plt
t = np.arange(0.01, 10.0, 0.001)
data1 = np.exp(t)
data2 = np.cos(0.4 * np.pi * t)
fig, ax1 = plt.subplots()
color = 'tab:orange'
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:cyan'
ax2.set_ylabel('cos', 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()
```

The output for the above code is as follows:

In the above code, we used the `twinx()`

function and we got twin axes sharing the x-axis.

## Summary:

The `twinx()`

and `twiny()`

functions are used when you want to show multiple scale for the data in a figure or if you want to have multiple plots in a single figure.