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pythonmatplotlibmplot3d

Reverse Z Axis on matplotlib 3D Plot


How would one reverse the order on the z axis of a 3D plot (i.e. negative is up, and positive is down)? The following code produces a cone with the base pointing downward; is there a command (like ax.reverse_zlim3d(True) or something?) that can be used to change the tick order?

The following code plots a cone with the base pointing downward. I would like to reverse the z-axis order so that it plots with the base pointing up, like an ice cream cone, with -1 at the top of the graph instead of the bottom.

from matplotlib import pyplot as p
from mpl_toolkits.mplot3d import Axes3D    # @UnusedImport

import numpy as np
from math import pi, cos, sin

z = np.arange(0, 1, 0.02)
theta = np.arange(0, 2 * pi + pi / 50, pi / 50)

fig = p.figure()
axes1 = fig.add_subplot(111, projection='3d')
for zval in z:
    x = zval * np.array([cos(q) for q in theta])
    y = zval * np.array([sin(q) for q in theta])
    axes1.plot(x, y, -zval, 'b-')
axes1.set_xlabel("x label")
axes1.set_ylabel("y label")
axes1.set_zlabel("z label")

p.show()

Cone Plot


Solution

  • Use the invert_zaxis method of the Axes3D:

    from matplotlib import pyplot as p
    from mpl_toolkits.mplot3d import Axes3D    # @UnusedImport
    
    import numpy as np
    from math import pi, cos, sin
    
    z = np.arange(0, 1, 0.02)
    theta = np.arange(0, 2 * pi + pi / 50, pi / 50)
    
    fig = p.figure()
    axes1 = fig.add_subplot(111, projection='3d')
    for zval in z:
        x = zval * np.array([cos(q) for q in theta])
        y = zval * np.array([sin(q) for q in theta])
        axes1.plot(x, y, -zval, 'b-')
    axes1.set_xlabel("x label")
    axes1.set_ylabel("y label")
    axes1.set_zlabel("z label")
    
    axes1.invert_zaxis()
    
    p.show()
    

    enter image description here