matplotlib subplots size with code examples

Matplotlib is a powerful plotting library for Python. One of its useful features is the ability to create subplots, which allows you to plot multiple figures in a single figure. In this article, we will explore how to control the size of subplots using code examples.

First, let's import the necessary libraries:

import matplotlib.pyplot as plt
import numpy as np

To create a subplot, we use the plt.subplots() function, which returns a figure and an array of axes. The first argument of the function is the number of rows, and the second argument is the number of columns. For example, to create a 2×2 grid of subplots, we can use the following code:

fig, axs = plt.subplots(2, 2)

To control the size of the subplots, we can use the figsize parameter of the plt.subplots() function. This parameter takes a tuple of width and height in inches. For example, to create a 2×2 grid of subplots with a width of 8 inches and a height of 6 inches, we can use the following code:

fig, axs = plt.subplots(2, 2, figsize=(8, 6))

Alternatively, we can also use the set_size_inches() method of the figure object to change the size of the subplots after they have been created. For example, to change the size of the above 2×2 grid of subplots to a width of 10 inches and a height of 8 inches, we can use the following code:

fig.set_size_inches(10, 8)

We can also use the set_size() method of the axes object to change the size of the subplots individually. This method takes the width and height of the subplot in inches. For example, to change the size of the first subplot in the above 2×2 grid to a width of 3 inches and a height of 2 inches, we can use the following code:

axs[0,0].set_size(3,2)

To illustrate the usage of the above methods, let's create a 2×2 grid of subplots with random data and change their size:

fig, axs = plt.subplots(2, 2, figsize=(8, 6))

# Generate some data
for i in range(2):
    for j in range(2):
        axs[i, j].plot(np.random.randn(50))

# Change size of subplots
fig.set_size_inches(10, 8)
axs[0,0].set_size(3,2)

# Show the plot
plt.show()

In this way, we can control the size of subplots in matplotlib using the figsize parameter of the plt.subplots() function, the set_size_inches() method of the figure object, and the set_size() method of the axes object.

It is to be noted that the size of subplots can also be controlled using the gridspec_kw parameter of the plt.subplots()
In addition to controlling the size of subplots, there are several other ways to customize the layout of subplots in matplotlib.

One way to control the spacing between subplots is to use the subplots_adjust() method of the figure object. This method takes several parameters, including wspace and hspace, which control the horizontal and vertical spacing between subplots, respectively. For example, to reduce the horizontal and vertical spacing between subplots in the above 2×2 grid, we can use the following code:

fig.subplots_adjust(wspace=0.2, hspace=0.2)

Another way to customize the layout of subplots is to use the GridSpec class, which allows for more fine-grained control over the layout of subplots. The GridSpec class takes the number of rows and columns of the grid as well as the width and height ratios of the subplots. We can then use the subplot2grid() function to create subplots at specific locations in the grid. For example, to create a 3×3 grid of subplots with the middle subplot spanning 2 rows and 2 columns, we can use the following code:

import matplotlib.gridspec as gridspec

gs = gridspec.GridSpec(3, 3)
ax1 = plt.subplot(gs[0, :])
ax2 = plt.subplot(gs[1, :-1])
ax3 = plt.subplot(gs[1:, -1])
ax4 = plt.subplot(gs[-1, 0])
ax5 = plt.subplot(gs[-1, -2])

Additionally, matplotlib also provides a subplot() function that can be used to create subplots at specific locations in a grid. This function takes three arguments: the number of rows, the number of columns, and the index of the subplot. The index is a single integer that ranges from 1 to the total number of subplots. For example, to create a 2×2 grid of subplots with the first subplot at the top left, the second subplot at the top right, the third subplot at the bottom left, and the fourth subplot at the bottom right, we can use the following code:

ax1 = plt.subplot(2, 2, 1)
ax2 = plt.subplot(2, 2, 2)
ax3 = plt.subplot(2, 2, 3)
ax4 = plt.subplot(2, 2, 4)

In conclusion, matplotlib provides a range of options for controlling the layout of subplots, including controlling the size of subplots, adjusting the spacing between subplots, and using the GridSpec and subplot() functions for more fine-grained control over the layout. With the above methods, you can create custom plots that best suit your data.

Popular questions

1. How do you control the size of subplots in matplotlib?

• The size of subplots in matplotlib can be controlled using the figsize parameter of the plt.subplots() function, the set_size_inches() method of the figure object, and the set_size() method of the axes object.

2. How do you adjust the spacing between subplots in matplotlib?

• The spacing between subplots in matplotlib can be adjusted using the subplots_adjust() method of the figure object. This method takes several parameters, including wspace and hspace, which control the horizontal and vertical spacing between subplots.

3. How do you use the GridSpec class to customize the layout of subplots in matplotlib?

• The GridSpec class in matplotlib allows for more fine-grained control over the layout of subplots. It takes the number of rows and columns of the grid as well as the width and height ratios of the subplots. We can then use the subplot2grid() function to create subplots at specific locations in the grid.

4. How do you use the subplot() function to create subplots in matplotlib?

• The subplot() function in matplotlib is used to create subplots at specific locations in a grid. It takes three arguments: the number of rows, the number of columns, and the index of the subplot. The index is a single integer that ranges from 1 to the total number of subplots.

5. Can you give an example of creating a custom layout of subplots using the GridSpec and subplot() functions in matplotlib?

• Yes, for example, to create a 3×3 grid of subplots with the middle subplot spanning 2 rows and 2 columns using the GridSpec and subplot() functions, we can use the following code:

import matplotlib.gridspec as gridspec

gs = gridspec.GridSpec(3, 3)
ax1 = plt.subplot(gs[0, :])
ax2 = plt.subplot(gs[1, :-1])
ax3 = plt.subplot(gs[1:, -1])
ax4 = plt.subplot(gs[-1, 0])
ax5 = plt.subplot(gs[-1, -2])

Alternatively, you can use the subplot() function to create subplots in a specific position in the grid.

Tag

Subplots