Skip to content
Related Articles

Related Articles

Improve Article

How to change Matplotlib color bar size in Python?

  • Last Updated : 03 Jan, 2021

Colorbar is a separate axis that provides a current colormap indicating mapping of data-points into colors. In this article, We are going to change Matplotlib color bar size in Python. There are several ways with which you can resize your color-bar or adjust its position. Let’s see it one by one.

Method 1: Resizing color-bar using shrink keyword argument

 Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.  

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning - Basic Level Course

Using the shrink attribute of colorbar() function we can scale the size of the colorbar. 

Syntax : matplotlib.pyplot.colorbar(mappable=None, shrink=scale)

Basically, we are multiplying by some factor to the original size of the color-bar. In the below example by using 0.5 as a factor, We are having the original color-bar size.

Example 1:  


# importing library
import matplotlib.pyplot as plt
# Some data to show as an image
data = [[1, 2, 3],
        [4, 5, 6]]
# Call imshow() to display 2-D data as an image
img = plt.imshow(data)
# Scaling colorbar by factor 0.5



Example 2: In this example, we are using factor 0.75. Similarly, you can use any factor to change the color-bar size. The default value of the shrink attribute is 1.


import matplotlib.pyplot as plt
import matplotlib.image as mpimg
fig, ax = plt.subplots()
# getting rid of axis
# Reading saved image from folder
img = mpimg.imread(r'img.jpg')
# displaying image
# Scaling by factor 0.75



Method 2: Using AxesDivider class

With this class, you can change the size of the colorbar axes however height will be the same as the current axes. Here we are using axes_divider.make_axes_locatable function which returns the AxisDivider object for our current axes in which our image is shown.



# importing libraries
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import make_axes_locatable
fig, ax = plt.subplots()
# Reading image from folder
img = mpimg.imread(r'img.jpg')
image = plt.imshow(img)
# Locating current axes
divider = make_axes_locatable(ax)
# creating new axes on the right
# side of current axes(ax).
# The width of cax will be 5% of ax
# and the padding between cax and ax
# will be fixed at 0.05 inch.
colorbar_axes = divider.append_axes("right",
# Using new axes for colorbar
plt.colorbar(image, cax=colorbar_axes)



My Personal Notes arrow_drop_up
Recommended Articles
Page :