Matplotlib - Setting Font Properties Globally

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Setting font properties globally in Matplotlib library involves configuring default font settings for the entire plot using plt.rcParams method. This is useful when we want to apply consistent font styles, sizes or families to all text elements in our visualizations without specifying them individually for each component.

It's important to note that we can tailor these settings based on our preferences and the visual style we want to achieve in our plots. We can adjust the values to match our desired font styles, sizes and families for a consistent and aesthetically pleasing appearance across our visualizations.

The following are the different settings that we can make by using the plt.rcParams method.

plt.rcParams['font.family'] = font_name

This sets the default font family for text elements such as 'sans-serif'. We can replace font_name with the available font families such as 'serif', 'monospace' or specific font names.

Example

In this example we are trying to set the font family to 'sans-serif' by using the plt.rcParams['font.family'].

import matplotlib.pyplot as plt
# Set font properties globally
plt.rcParams['font.family'] = 'sans-serif'
# Create a plot
plt.plot([1, 2, 3], [4, 5, 6])
plt.xlabel('X-axis Label')
plt.ylabel('Y-axis Label')
plt.title('Font Family setting')
plt.show()

Output

plt.rcParams['font.size'] = font_size

We can specify the default font size for text elements in numerical values as per the requirement. This ensures that all text elements use this font size unless overridden for specific components.

Example

In this example we are specifying the fontsize as 8 points to the plt.rcParams['font.size'] to display font size globally all over the plot.

import matplotlib.pyplot as plt
# Set font properties globally
plt.rcParams['font.size'] = 8
# Create a plot
plt.plot([1, 2, 3], [4, 5, 6])
plt.xlabel('X-axis Label')
plt.ylabel('Y-axis Label')
plt.title('Font Size setting')
plt.show()

Output

plt.rcParams['font.style'] = 'fontstyle'

We can define the font style such as italic etc., as per our interest to the plt.rcParams['font.style']. This applies the defined appearance to text elements throughout the plot.

Example

In this example we are specifying the font style as italic to the plt.rcParams['font.style'].

import matplotlib.pyplot as plt
# Set font properties globally
plt.rcParams['font.style'] = 'italic'
# Create a plot
plt.plot([1, 2, 3], [4, 5, 6])
plt.xlabel('X-axis Label')
plt.ylabel('Y-axis Label')
plt.title('Font Style setting')
plt.show()

Output

plt.rcParams['font.weight'] = font_weight

By using this we can set the font weight such as 'bold' etc. This makes the characters in text elements appear in the defined style as per the user requirement.

Example

Here in this example we are specifying the font weight as bold to the plt.rcParams['font.weight'].

import matplotlib.pyplot as plt
# Set font properties globally
plt.rcParams['font.weight'] = 'bold'
# Create a plot
plt.plot([1, 2, 3], [4, 5, 6])
plt.xlabel('X-axis Label')
plt.ylabel('Y-axis Label')
plt.title('Font weight setting')
plt.show()

Output

Note − By setting these parameters globally using plt.rcParams we can ensure that these default font properties are applied to all text elements in our Matplotlib plots. When we create labels, titles or other text components they will inherit these global settings unless we specify different properties locally.

Change the font properties of a Matplotlib colorbar label

In this example we are changing the font properties of a matplotlib colorbar label.

Example

import numpy as np
import matplotlib.pyplot as plt
plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True
x, y = np.mgrid[-1:1:100j, -1:1:100j]
z = (x + y) * np.exp(-5.0 * (x ** 2 + y ** 2))
plt.imshow(z, extent=[-1, 1, -1, 1])
cb = plt.colorbar(label='my color bar label')
plt.show()

Output

Setting the size of the plotting canvas

Here in this example we are setting the size of the plotting canvas in matplotlib.

Example

import numpy as np
from matplotlib import pyplot as plt
plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True
x = np.linspace(-2, 2, 100)
y = np.sin(x)
plt.plot(x, y)
plt.show()

Output

Auto adjust font size in Seaborn heatmap using Matplotlib

Here we are auto adjusting the font size in seaborn heatmap by using the Matplotlib library.

Example

import numpy as np
import seaborn as sns
from matplotlib import pyplot as plt
import pandas as pd
plt.rcParams["figure.figsize"] = [7.00, 3.50]
plt.rcParams["figure.autolayout"] = True
d = {
   'y=1/x': [1 / i for i in range(1, 10)],
   'y=x': [i for i in range(1, 10)],
   'y=x^2': [i * i for i in range(1, 10)],
   'y=x^3': [i * i * i for i in range(1, 10)]
}
df = pd.DataFrame(d)
ax = sns.heatmap(df, vmax=1)
plt.xlabel('Mathematical Expression', fontsize=16)
plt.show()

Output

Set the font size of Matplotlib axis Legend

In this example we are setting the font size of matplotlib axis legend

Example

import numpy as np
from matplotlib import pyplot as plt
import matplotlib
plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True
x = np.linspace(1, 10, 50)
y = np.sin(x)
plt.plot(x, y, c="red", lw=7, label="y=sin(x)")
plt.title("Sine Curve")
matplotlib.rcParams['legend.fontsize'] = 20
plt.legend(loc=1)
plt.show()

Output

Modify the font size in Matplotlib-venn

To work with the Matplotlib-venn, first we have to install the package by using the below code. If previously installed we can import directly.

pip install matplotlib-venn

Example

In this example we are modifying the font size in Matplotlib-venn by using the set_fontsize() method.

from matplotlib import pyplot as plt
from matplotlib_venn import venn3
plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True
set1 = {'a', 'b', 'c', 'd'}
set2 = {'a', 'b', 'e'}
set3 = {'a', 'd', 'f'}
out = venn3([set1, set2, set3], ('Set1', 'Set2', 'Set3'))
for text in out.set_labels:
   text.set_fontsize(25)
for text in out.subset_labels:
   text.set_fontsize(12)
plt.show()

Output

Change xticks font size

To change the font size of xticks in a matplotlib plot we can use the fontsize parameter.

Example

from matplotlib import pyplot as plt
import numpy as np
# Set the figure size
plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True
# x and y data points
x = np.linspace(-5, 5, 100)
y = np.sin(x)
plt.plot(x, y)
# Set the font size of xticks
plt.xticks(fontsize=25)
# Display the plot
plt.show()

Output