Python Data Science Handbook, 2nd Edition

Chapter 27. Simple Scatter Plots

Another commonly used plot type is the simple scatter plot, a close cousin of the line plot. Instead of points being joined by line segments, here the points are represented individually with a dot, circle, or other shape. We’ll start by setting up the notebook for plotting and importing the packages we will use:

In [1]: %matplotlib inline
        import matplotlib.pyplot as plt
        plt.style.use('seaborn-whitegrid')
        import numpy as np

Scatter Plots with plt.plot

In the previous chapter we looked at using plt.plot/ax.plot to produce line plots. It turns out that this same function can produce scatter plots as well (see Figure 27-1).

In [2]: x = np.linspace(0, 10, 30)
        y = np.sin(x)

        plt.plot(x, y, 'o', color='black');

Figure 27-1. Scatter plot example

The third argument in the function call is a character that represents the type of symbol used for the plotting. Just as you can specify options such as '-' or '--' to control the line style, the marker style has its own set of short string codes. The full list of available symbols can be seen in the documentation of plt.plot, or in Matplotlib’s online documentation. Most of the possibilities are fairly intuitive, and a number of the more common ones are demonstrated here (see Figure 27-2).

In [3]: rng = np.random.default_rng(0)
        for marker in ['o', '.', ',', 'x', '+', 'v', '^', '<', '>', 's', 'd']:
            plt.plot