Matplotlib is a powerful data visualization library in Python that provides a wide range of tools for creating high-quality 2D and 3D plots. One important aspect of creating effective visualizations is customizing the size of the figures to suit your needs. In this tutorial, we will explore how to change the size of figures drawn with Matplotlib.
Introduction to Figure Sizes
When you create a figure in Matplotlib, it has a default size that can be adjusted using various methods. The figure size is specified in inches, and you can set it when creating a new figure or modify an existing one.
Setting Figure Size When Creating a New Figure
To set the figure size when creating a new figure, you can use the figsize parameter of the figure function from Matplotlib’s pyplot module. Here is an example:
import matplotlib.pyplot as plt
# Create a new figure with a specified size
plt.figure(figsize=(8, 6))
# Plot some data
plt.plot([1, 2, 3, 4, 5])
# Show the plot
plt.show()
In this example, we create a new figure with a width of 8 inches and a height of 6 inches.
Modifying an Existing Figure
If you have already created a figure and want to modify its size, you can use the set_size_inches method of the Figure object. Here is how you can do it:
import matplotlib.pyplot as plt
# Create a new figure
fig = plt.figure()
# Plot some data
plt.plot([1, 2, 3, 4, 5])
# Set the figure size to 10 inches wide and 6 inches tall
fig.set_size_inches(10, 6)
# Show the plot
plt.show()
In this example, we first create a new figure using plt.figure(), then set its size to 10 inches wide and 6 inches tall using fig.set_size_inches(10, 6).
Using rcParams
Another way to customize the figure size is by using Matplotlib’s rcParams. You can set the default figure size for all figures in your script or notebook by modifying the figure.figsize parameter:
import matplotlib.pyplot as plt
# Set the default figure size to 10 inches wide and 6 inches tall
plt.rcParams["figure.figsize"] = (10, 6)
# Create a new figure
plt.figure()
# Plot some data
plt.plot([1, 2, 3, 4, 5])
# Show the plot
plt.show()
In this example, we set the default figure size to 10 inches wide and 6 inches tall using plt.rcParams["figure.figsize"] = (10, 6). All subsequent figures created in the script or notebook will have this size unless explicitly overridden.
Converting Between Units
The figsize parameter expects values in inches. If you want to specify the figure size in centimeters, you can convert it by dividing the value in centimeters by 2.54 (since 1 inch is equal to 2.54 centimeters).
# Convert 10 cm to inches
width_in_inches = 10 / 2.54
# Create a new figure with a specified size in inches
plt.figure(figsize=(width_in_inches, width_in_inches))
Best Practices
When customizing figure sizes, keep the following best practices in mind:
- Use consistent units throughout your script or notebook.
- Avoid setting the figure size too small, as it may make the plot difficult to read.
- Consider the aspect ratio of your plot when choosing a figure size.
By following these guidelines and using the methods described in this tutorial, you can effectively customize the size of your figures with Matplotlib to create high-quality visualizations that communicate your data insights clearly.