.scatter()

The .scatter() method in the matplotlib library is used to draw a scatter plot, showing a relationship between variables.

Syntax

matplotlib.pyplot.scatter(x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, edgecolors, plotnonfinite)

Both ‘x’ and ‘y’ parameters are required, and represent float or array-like objects. Other parameters are optional and modify plot features like marker size and/or color.

.scatter() takes the following arguments:

• x and y: Positional arguments of type float or array.
• s: A float or an array (of size equal to x or y) specifying marker size.
• c: An array or list specifying marker color.
• marker: Sets the marker style, specified with a shorthand code (e.g. “.”: point, “o”: circle) or an instance of the class.
• cmap: A Colormap instance used to map scalar data to colors. (Default: “viridis”)
• norm: Normalization method used to scale scalar data to a range of (0 to 1) before mapping. Linear scaling is default.
• vmin and vmax: Sets the data range for the colormap (if norm is not specified).
• alpha: Sets the transparency value of the markers - range between 0 (transparent) and 1 (opaque).
• linewidths: Sets the linewidth of the marker edge.
• edgecolors: Sets the edge color of the marker.
• plotnonfinite: Boolean value determining whether to plot nonfinite (inf, -inf, nan) values. Default is False.

Examples

Examples below demonstrate the use of .scatter() to plot values and vary marker properties.

import matplotlib.pyplot as plt

x1 = [5, 13, 21, 28, 31, 34, 39, 44, 49]
y1 = [14, 28, 44, 56, 67, 53, 47, 30, 11]

plt.scatter(x1, y1)
plt.show()

Output:

import matplotlib.pyplot as plt

x2 = [11, 22, 33, 44, 55]
y2 = [11, 22, 33, 44, 55]

plt.scatter(x2, y2, s=150, c='#88c988', linewidth=3, marker='p' , edgecolor='#175E17', alpha=0.75)
plt.show()

Output: