Setting a relative frequency in a Matplotlib histogram

To set a relative frequency in a matplotlib histogram, we can take the following steps −

• Create a list of numbers for data and bins.

• Compute the histogram of a set of data, using histogram() method.

• Get the hist and edges from the histogram.

• Find the frequency of the histogram.

• Make a bar with bins (step 1) and freq data (step 4).

• To display the figure, use show() method.

Example

import numpy as np
from matplotlib import pyplot as plt
plt.rcParams["figure.figsize"] = [7.00, 3.50]
plt.rcParams["figure.autolayout"] = True
a = [-0.125, .15, 8.75, 72.5, -44.245, 88.45]
bins = np.arange(-180, 181, 20)
hist, edges = np.histogram(a, bins)
freq = hist/float(hist.sum())
plt.bar(bins[:-1], freq, width=20, align="edge", ec="k", color='red')
plt.show()

Output