Rotate Axis Labels in Matplotlib with Examples and Output

The matplotlib library in Python comes with a number of methods to build highly customizable plots. In this tutorial, we will look at how to rotate axis labels in a matplotlib plot with the help of some examples.

How to rotate axis labels in matplotlib?

• If you’re working with a single plot, you can use the matplotlib.pyplot.xticks() function to rotate the labels on the x-axis, pass the degree of rotation to the rotation parameter. You can similarly rotate y-axis labels using matplotlib.pyplot.yticks() function.
• If you’re working with subplots, for each subplot, use the subplot axes object’s set_xticklabels() to rotate the labels on the x-axis. Note that you have to pass the labels to use along with the degree of rotation to this function. You can similarly rotate the y-axis labels of a subplot using its axes object’s set_ytickslabels() function.

Let’s now look at some examples of using the above syntax –

Example 1 – Rotate axis labels for a single plot

Let’s create a scatter plot with some data.

import matplotlib.pyplot as plt

# x values - years
x = [2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020]
# y values - 1 USD in INR
y = [46.67, 53.44, 56.57, 62.33, 62.97, 66.46, 67.79, 70.09, 70.39, 76.38]

# plot x and y on scatter plot
plt.scatter(x, y)

# add axes labels
plt.xlabel('Year')
plt.ylabel('1USD in INR')

Output:

You can see that the labels, by default, are not rotated. We generally rotate labels when they’re too long and overlap each other and thus rotating them helps with the label readability.

Let’s draw the above plot again but this time with the x-axis labels rotated 45 degrees.

# plot x and y on scatter plot
plt.scatter(x, y)

# add axes labels
plt.xlabel('Year')
plt.ylabel('1USD in INR')

# rotate x-axis labels
plt.xticks(rotation=45)

# plot
plt.draw()

Output:

You can see that the axis labels are now rotated by 45 degrees. You can also change the horizontal alignment using the ha parameter. By default, the labels are aligned to the center of the ticks.

# plot x and y on scatter plot
plt.scatter(x, y)

# add axes labels
plt.xlabel('Year')
plt.ylabel('1USD in INR')

# rotate x-axis labels
plt.xticks(rotation=45, ha='right')

# plot
plt.draw()

Output:

Here, we changed the horizontal alignment to right.

You can similarly rotate labels on the y-axis using the matplotlib.pyplot.yticks() function.

Example 2 – Rotate labels in subplots

When working with subplots, you can use the subplot’s axes object’s set_xticklabels() function to rotate the label for each subplot. Note that you have to also pass the label values as an argument to this function. You can get the xticklabels using the axes objects get_xticklabels() function.

Let’s create two subplots.

fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(10, 5))

# plot the first subplot
ax1.scatter(x, y)
# add axis labels
ax1.set_xlabel('Year')
ax1.set_ylabel('1USD in INR')

# plot the second subplot
ax2.scatter(x, y)
# add axis labels
ax2.set_xlabel('Year')
ax2.set_ylabel('1USD in INR')

Output:

We used the same data values for the two plots but that’s not important. What we want to show is how to set the rotation for each subplot.

Let’s now rotate the x-axis labels for the first subplot by 45 degrees and that of the second subplot by 90 degrees.

fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(10, 5))

# plot the first subplot
ax1.scatter(x, y)
# add axis labels
ax1.set_xlabel('Year')
ax1.set_ylabel('1USD in INR')
# draw the plot
plt.draw()
# rotate x-axis labels
ax1.set_xticklabels(ax1.get_xticklabels(), rotation=45)

# plot the second subplot
ax2.scatter(x, y)
# add axis labels
ax2.set_xlabel('Year')
ax2.set_ylabel('1USD in INR')
# draw the plot
plt.draw()
# rotate x-axis labels
ax2.set_xticklabels(ax1.get_xticklabels(), rotation=90)

Output:

We get rotated the xticklabels for the subplots separately. Two important things to notice in the above code are –

1. We need the explicitly pass the axis labels as an argument to the set_xticklabels() function. You can use the axes object’s get_xticklabels() function to get the corresponding label values.
2. We need to draw the plot before adding the labels, (we draw the chart using plt.draw() in the above example), this is because matplotlib attaches the labels after the chart is drawn.

You can similarly rotate the yticklabels in subplots using the respective axes object’s set_yticklabels() function.

You might also be interested in –

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• Show Gridlines on Matplotlib Plots
• How to Label Points on a Scatter Plot in Matplotlib?
• Reverse Axes of a Plot in Matplotlib