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Display two Sympy plots as two Matplotlib subplots

This code

from sympy import *
x=Symbol('x')
p1 = plot(x**2,(x,-2,2))
p2 = plot(x**3,(x,-2,2))

results in two separate plots.

Instead of two separate plots, I want to display them with matplotlib as subplots:

import matplotlib.pyplot as plt
fig = plt.figure()
ax1 = fig.add_subplot(121)
ax2 = fig.add_subplot(122)
plt.show()

How can I add p1 and p2, so that they are displayed as subplots inside the matplotlib figure?

like image 348
M. Heuer Avatar asked Oct 18 '17 13:10

M. Heuer


1 Answers

The problem is that sympy Plot creates its own figure and axes. It is not meant to draw to an existing axes.

You may however replace the axes the plot is drawn to by an existing axes prior to showing the sympy plot.

from sympy import Symbol,plot
import matplotlib.pyplot as plt

def move_sympyplot_to_axes(p, ax):
    backend = p.backend(p)
    backend.ax = ax
    backend.process_series()
    backend.ax.spines['right'].set_color('none')
    backend.ax.spines['bottom'].set_position('zero')
    backend.ax.spines['top'].set_color('none')
    plt.close(backend.fig)


x=Symbol('x')
p1 = plot(x**2,(x,-2,2), show=False)
p2 = plot(x**3,(x,-2,2), show=False)


fig, (ax,ax2) = plt.subplots(ncols=2)
move_sympyplot_to_axes(p1, ax)
move_sympyplot_to_axes(p2, ax2)

plt.show()

enter image description here

like image 129
ImportanceOfBeingErnest Avatar answered Oct 05 '22 21:10

ImportanceOfBeingErnest