["python","matplotlib","axis","aspect-ratio","matplotlib-3d"]
How to set the 'equal' aspect ratio for all axes (x, y, z)

When I set up an equal aspect ratio for a 3d graph, the z-axis does not change to 'equal'. So this: fig = pylab.figure() mesFig = fig.gca(projection='3d', adjustable='box') mesFig.axis('equal') mesFig.plot(xC, yC, zC, 'r.') mesFig.plot(xO, yO, zO, 'b.') pyplot.show() Gives me the following: Where obviously the unit length of z-axis is not equal to x- and y- units. How can I make the unit length of all three axes equal? All the solutions I found did not work.
I believe matplotlib does not yet set correctly equal axis in 3D... But I found a trick some times ago (I don't remember where) that I've adapted using it. The concept is to create a fake cubic bounding box around your data. You can test it with the following code: from mpl_toolkits.mplot3d import Axes3D from matplotlib import cm import matplotlib.pyplot as plt import numpy as np fig = plt.figure() ax = fig.add_subplot(projection='3d') ax.set_aspect('equal') X = np.random.rand(100)*10+5 Y = np.random.rand(100)*5+2.5 Z = np.random.rand(100)*50+25 scat = ax.scatter(X, Y, Z) # Create cubic bounding box to simulate equal aspect ratio max_range = np.array([X.max()-X.min(), Y.max()-Y.min(), Z.max()-Z.min()]).max() Xb = 0.5*max_range*np.mgrid[-1:2:2,-1:2:2,-1:2:2][0].flatten() + 0.5*(X.max()+X.min()) Yb = 0.5*max_range*np.mgrid[-1:2:2,-1:2:2,-1:2:2][1].flatten() + 0.5*(Y.max()+Y.min()) Zb = 0.5*max_range*np.mgrid[-1:2:2,-1:2:2,-1:2:2][2].flatten() + 0.5*(Z.max()+Z.min()) # Comment or uncomment following both lines to test the fake bounding box: for xb, yb, zb in zip(Xb, Yb, Zb): ax.plot([xb], [yb], [zb], 'w') plt.grid() plt.show() z data are about an order of magnitude larger than x and y, but even with equal axis option, matplotlib autoscale z axis: But if you add the bounding box, you obtain a correct scaling: