How to Show Colorbar in Matplotlib
In this tutorial, we will discuss how to show a colorbar in a matplotlib figure in Python.
To create a colorbar we have to use the matplotlib.pyplot.colorbar()
function.
The following code shows a simple example of this.
import random
import matplotlib.pyplot as plt
s_x = random.sample(range(0, 100), 20)
s_y = random.sample(range(0, 100), 20)
s = plt.scatter(s_x, s_y, c=s_x, cmap="viridis")
c = plt.colorbar()
In the above example, we created a simple colorbar placed outside of the plot. We specified the colormap using the cmap
parameter.
We can also specify the axes in which we wish to show the colorbar. If we wish, we can add it over the axes of the plot.
For example,
import random
import matplotlib.pyplot as plt
s_x = random.sample(range(0, 100), 20)
s_y = random.sample(range(0, 100), 20)
fig, ax = plt.subplots()
cax = fig.add_axes([0.27, 0.8, 0.5, 0.05])
im = ax.scatter(s_x, s_y, c=s_x, cmap="viridis")
fig.colorbar(im, cax=cax, orientation="horizontal")
In the above example, we used the subplots()
function to get the figure and axes objects and use it to create the axes for the colorbar. We specified this using the cax
parameter in the colorbar()
function.
Also, note the use of the orientation
parameter which altered the orientation of the final color bar. Apart from this, we can use different parameters to control the shape and size of the colorbar. For example, shrink
can reduce the size of the colorbar by a small margin, aspect
, which is the ratio of the sides of the bar, and there are many more.
Manav is a IT Professional who has a lot of experience as a core developer in many live projects. He is an avid learner who enjoys learning new things and sharing his findings whenever possible.
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