+
+ The user also can pass another plot to the :meth:`plot` method. This can be useful to compare two polyhedrons on the same axis. This example illustrates the union of two squares.
+
+ >>> from linpy import *
+ >>> import matplotlib.pyplot as plt
+ >>> from matplotlib import pylab
+ >>> x, y = symbols('x y')
+ >>> square1 = Le(0, x) & Le(x, 2) & Le(0, y) & Le(y, 2)
+ >>> square2 = Le(1, x) & Le(x, 3) & Le(1, y) & Le(y, 3)
+ >>> fig = plt.figure()
+ >>> plot = fig.add_subplot(1, 1, 1, aspect='equal')
+ >>> square1.plot(plot, facecolor='red', alpha=0.3)
+ >>> square2.plot(plot, facecolor='blue', alpha=0.3)
+ >>> squares = Polyhedron(square1 + square2)
+ >>> squares.plot(plot, facecolor='blue', alpha=0.3)
+ >>> pylab.show()
+
+ .. figure:: images/union.jpg
+ :align: center
+
+
+