📂Programing

Drawing Subplots at Desired Arbitrary Locations or Overlapping in Python matplotlib

Overview

Using plt.subplot or gridspec, you can create subplots in simple or complex grid-based layouts. This article introduces a method to draw subplots at completely arbitrary positions, independent of the grid system.

Code

• fig.add_axes([left, bottom, width, height])

By using add_axes, you can create a new subplot at a desired location on the figure. The area of the subplot is determined by the input arguments [left, bottom, width, height]. Each item represents a ratio of the total figure, thus, $0 \le$ left, bottom, width, height $\le 1$ must be satisfied. For example, fig.add_axes([0.1, 0.1, 0.2, 0.3]) creates a subplot that is detached from the left by $1/10$ of the total width, from the bottom by $1/10$ of the total height, and the size of the subplot is proportional to $0.2 \times 0.3$ of the total figure size. The reference point for the position is the bottom-left corner of the subplot.

import matplotlib.pyplot as plt
import numpy as np

fig = plt.figure()

ax1 = fig.add_axes([0.1, 0.1, 0.2, 0.3])
ax1.plot(np.random.randn(10))

plt.show()

Because you can draw at absolutely any location, it is also possible to overlap subplots. The first drawn subplot will lie underneath.

fig = plt.figure()

ax1 = fig.add_axes([0.1, 0.1, 0.4, 0.8])
ax1.plot(np.random.randn(10))

ax2 = fig.add_axes([0.4, 0.5, 0.4, 0.4])
plt.bar(np.arange(10), np.random.randn(10))

ax3 = fig.add_axes([0.7, 0.4, 0.2, 0.2])
ax3.scatter(np.random.randn(10), np.random.randn(10))

plt.show()

Environment

• OS: Windows11
• Version: Python 3.9.13, matplotlib==3.6.2, numpy==1.23.5