You can use the following basic syntax to calculate the cumulative distribution function (CDF) in Python:

#sort data x = np.sort(data) #calculate CDF values y = 1. * np.arange(len(data)) / (len(data) - 1) #plot CDF plt.plot(x, y)

The following examples show how to use this syntax in practice.

**Example 1: CDF of Random Distribution**

The following code shows how to calculate and plot a cumulative distribution function (CDF) for a random sample of data in Python:

import numpy as np import matplotlib.pyplot as plt #define random sample of data data = np.random.randn(10000) #sort data x = np.sort(data) #calculate CDF values y = 1. * np.arange(len(data)) / (len(data) - 1) #plot CDF plt.plot(x, y) plt.xlabel('x')

The x-axis displays the raw data values and the y-axis displays the corresponding CDF values.

**Example 2: CDF of Normal Distribution**

If you’d like to plot the cumulative distribution function of a known distribution (such as the normal distribution) then you can use the following functions from the SciPy library:

import numpy as np import scipy import matplotlib.pyplot as plt #generate data from normal distribution data = np.random.randn(1000) #sort data x = np.sort(data) #calculate CDF values y = scipy.stats.norm.cdf(x) #plot CDF plt.plot(data_sorted, norm_cdf) #plot CDF plt.plot(x, y) plt.xlabel('x')

**Additional Resources**

CDF vs. PDF: What’s the Difference?

How to Make a Bell Curve in Python

How to Calculate Z-Scores in Python

There are mistakes in the second code example – data_sorted isn’t defined.