Matplotlib.ticker.PercentFormatter class in Python

Matplotlib is an amazing visualization library in Python for 2D plots of arrays. Matplotlib is a multi-platform data visualization library built on NumPy arrays and designed to work with the broader SciPy stack.

matplotlib.ticker.PercentFormatter

The matplotlib.ticker.PercentFormatter class is used to format numbers as a percentage.

Syntax: class matplotlib.ticker.PercentFormatter(xmax=100, decimals=None, symbol=’%’, is_latex=False)

Parameters:

• xmax: It is a float value that determines how the number is converted into a percentage.
• decimals: It is either an integer value or None. It determines the number of decimal places to place after the point. If None (the default), the number will be computed automatically.
• symbol : It is either a string or none that gets appended to the label.
• is_latex: It is a boolean value. If False, reserved LaTeX characters in symbol are eliminated.

Example 1:

import pandas as pd
import numpy as np
import matplotlib.ticker as mtick
from matplotlib.ticker import PercentFormatter

df = pd.DataFrame(np.random.randn(100, 5))

ax = df.plot()
ax.yaxis.set_major_formatter(mtick.PercentFormatter(5.0))

Output:

Example 2:

import matplotlib.pyplot as plt
import numpy as np
import matplotlib.ticker as mtick
from matplotlib.ticker import PercentFormatter

data = [8, 12, 15, 17, 18, 18.5]
perc = np.linspace(0, 100, len(data))

fig = plt.figure(1, (7, 4))
ax = fig.add_subplot(1, 1, 1)

ax.plot(perc, data)

xticks = mtick.PercentFormatter(0.5)
ax.xaxis.set_major_formatter(xticks)

plt.show()

Output: