Rotation of colorbar tick labels in Matplotlib

Last Updated : 24 Jan, 2021

Colorbar is an axis that indicates the mapping of data values to the colors used in plot. The colorbar() function in pyplot module of matplotlib adds a colorbar to a plot indicating the color scale.

Sometimes it is desirable to rotate the ticklabels for better visualization and understanding. To change the rotation of colorbar ticklabels desired angle of rotation is provided in:

cbar.ax.set_xticklabels, if colorbar orientation is horizontal
cbar.ax.set_yticklabels, if colorbar orientation is vertical

Positive value of angle corresponds to counterclockwise rotation, while negative value corresponds to clockwise rotation. Also, we can use "vertical" and "horizontal" values for rotation instead of numeric value of angle. These are equivalent to 0° and +90° respectively.

Steps to rotate colorbar ticklabels :

Plot a figure
Plot corresponding colorbar
Provide ticks and ticklabels
Set rotation of ticklabels to desired angle

Example 1: Following program demonstrates horizontal color bar with 45 degrees rotation of colorbar ticklabels.

Python3

# Import libraries
import matplotlib.pyplot as plt
import numpy as np

# Plot image
a = np.random.random((10, 10))
plt.imshow(a, cmap='gray')

# Plot horizontal colorbar
cbar = plt.colorbar(
    orientation="horizontal", fraction=0.050)

# Set ticklabels
labels = [0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6,
          0.7, 0.8, 0.9, 1]
cbar.set_ticks(labels)

# Rotate colorbar ticklabels by 45 degrees
# anticlockwise
cbar.ax.set_xticklabels(labels, rotation=45)

plt.show()

Output:

Example 2: Following program demonstrates horizontal color bar with -45 degrees rotation of colorbar ticklabels.

Python3

# Import libraries
import matplotlib.pyplot as plt
import numpy as np

# Plot image
a = np.random.random((10, 10))
plt.imshow(a, cmap='gray')

# Plot horizontal colorbar
cbar = plt.colorbar(
    orientation="horizontal", fraction=0.050)

# Set ticklabels
labels = [0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6,
          0.7, 0.8, 0.9, 1]
cbar.set_ticks(labels)

# Rotate colorbar ticklabels by 45 degrees clockwise
cbar.ax.set_xticklabels(labels, rotation=-45)

plt.show()

Output:

Example 3: Following program demonstrates vertical color bar with 30 degrees rotation of colorbar ticklabels.

Python3

# Import libraries
import matplotlib.pyplot as plt
import numpy as np

# Plot image
a = np.random.random((10, 10))
plt.imshow(a, cmap='gray')

# Plot vertical colorbar
cbar = plt.colorbar(
    orientation="vertical", fraction=0.050)

# Set ticklabels
labels = [0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6,
          0.7, 0.8, 0.9, 1]
cbar.set_ticks(labels)

# Rotate colorbar ticklabels by 30 degrees
# anticlockwise
cbar.ax.set_yticklabels(labels, rotation=30)

plt.show()

Output:

Example 4: Following program demonstrates vertical color bar with -30 degrees rotation of colorbar ticklabels.

Python3

# Import libraries
import matplotlib.pyplot as plt
import numpy as np

# Plot image
a = np.random.random((10, 10))
plt.imshow(a, cmap='gray')

# Plot vertical colorbar
cbar = plt.colorbar(
    orientation="vertical", fraction=0.050)

# Set ticklabels
labels = [0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6,
          0.7, 0.8, 0.9, 1]
cbar.set_ticks(labels)

# Rotate colorbar ticklabels by 30 degrees clockwise
cbar.ax.set_yticklabels(labels, rotation=-30)

plt.show()

Output:

Example 5: Following program demonstrates horizontal color bar with vertical rotation of colorbar ticklabels.

Python3

# Import libraries
import matplotlib.pyplot as plt
import numpy as np

# Plot image
a = np.random.random((10, 10))
plt.imshow(a, cmap='gray')

# Plot horizontal colorbar
cbar = plt.colorbar(
    orientation="horizontal", fraction=0.050)

# Set ticklabels
labels = [0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6,
          0.7, 0.8, 0.9, 1]
cbar.set_ticks(labels)

# Rotate colorbar ticklabels by 90 degrees
# anticlockwise using "vertical" value
cbar.ax.set_xticklabels(labels,
                        rotation="vertical")

plt.show()

Output:

Example 6: Following program demonstrates vertical color bar with 270 degrees rotation of colorbar ticklabels.

Python3

# Import libraries
import matplotlib.pyplot as plt
import numpy as np

# Plot image
a = np.random.random((10, 10))
plt.imshow(a, cmap='gray')

# Plot vertical colorbar
cbar = plt.colorbar(
    orientation="vertical", fraction=0.050)

# Set ticklabels
labels = [0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6,
          0.7, 0.8, 0.9, 1]
cbar.set_ticks(labels)

# Rotate colorbar ticklabels by 270 degrees
# anticlockwise
cbar.ax.set_yticklabels(labels, rotation=270)
plt.show()