matplotlib 3D绘图中等高线图投影显示不正确

Question

我在尝试绘制一个随机行走者在三维空间中位置的等高线图，分别在xy平面、xz平面和yz平面上。绘制xy平面时，我得到了一个正常的等高线图，但在xz和平面上却不太对劲，显示出一些奇怪的分布，尤其是在零线附近。请给我一些建议，告诉我该如何解决这个问题。

我是在Jupyter Notebook（Python）中绘制这个图的。下面附上了我的代码片段和我得到的图。如果问题解决了，请提供一个新的图。

import numpy as np
import matplotlib.pyplot as plt
from matplotlib import cm

stepsize = 0.5
num_steps = 250
num_trials = 10**3

final_path = []

for _ in range(num_trials+1):
    pos = np.array([0.0,0.0,0.0])
    for _ in range(num_steps+1):
        pos= pos+  np.random.normal(0,0.5,3)
    final_path.append(list(pos))

final_path = np.array(final_path)

x = final_path[:,0]
y = final_path[:,1]
z = final_path[:,2]

fig = plt.figure(figsize = (15,12)) 
ax = fig.add_subplot(projection = '3d', computed_zorder = False)
ax.scatter(x,y,z, c = 'blue', s = 40, zorder = 2)
# ax.plot(x, y, z, 'k-',  linewidth=0.5, zorder = 2)

ax.scatter(x,y, zs = min(z), zdir = 'z', color = 'black',s = 8, zorder = 1)
ax.scatter(x,z, zs = max(y), zdir = 'y', color = 'black',s = 8, zorder = 1)
ax.scatter(y,z, zs = min(x), zdir = 'x', color = 'black',s = 8, zorder = 1)

counts_xy, xedges, yedges = np.histogram2d(x, y, bins=25)
x_grid_xy, y_grid_xy = np.meshgrid(np.linspace(min(x), max(x), 25), np.linspace(min(y), max(y), 25))

counts_xz, xedges, zedges = np.histogram2d(x, z, bins=25)
x_grid_xz, z_grid_xz = np.meshgrid(np.linspace(min(x), max(x), 25), np.linspace(min(z), max(z), 25))

counts_yz, yedges, zedges = np.histogram2d(y, z, bins=25)
y_grid_yz, z_grid_yz = np.meshgrid(np.linspace(min(y), max(y), 25), np.linspace(min(z), max(z), 25))

ax.contourf(x_grid_xy, y_grid_xy, counts_xy.T, zdir='z', offset=min(z), levels = 25, cmap='Reds', zorder=0)
ax.contourf(x_grid_xz, z_grid_xz, counts_xz.T, zdir='y', offset=max(y), levels = 25, cmap='Greens', zorder=0)
ax.contourf(y_grid_yz, z_grid_yz, counts_yz.T, zdir='x', offset=min(x), levels = 25, cmap='Blues', zorder=0)

ax.set_xlim(min(x),max(x))
ax.set_ylim(min(y),max(y))
ax.set_zlim(min(z),max(z))
ax.set_xlabel('X')
ax.set_ylabel('Y')
ax.set_zlabel('Z')
ax.set_title('Walker\'s Position in 3D Space')

plt.show()

这是随机行走者经过1000次试验后的位置信息，以及在xy、xz和yz平面上的等高线投影。

我试着在ChatGPT中寻找解决方案，但也没有成功。我用以下代码行来绘制等高线图，但在这种情况下，xy平面的等高线正常，而xz和yz平面的等高线却如图所示。

counts_xy, xedges, yedges = np.histogram2d(x, y, bins=25)
x_grid_xy, y_grid_xy = np.meshgrid(xedges[:-1], yedges[:-1])

counts_xz, xedges, zedges = np.histogram2d(x, z, bins=25)
x_grid_xz, z_grid_xz = np.meshgrid(xedges[:-1], zedges[:-1])

counts_yz, yedges, zedges = np.histogram2d(y, z, bins=25)
y_grid_yz, z_grid_yz = np.meshgrid(yedges[:-1], zedges[:-1])

ax.contourf(x_grid_xy, y_grid_xy, counts_xy.T, zdir='z', offset=min(z), levels=50, cmap='Reds', zorder=0)
ax.contourf(x_grid_xz, z_grid_xz, counts_xz.T, zdir='y', offset=max(y), levels=50, cmap='Greens', zorder=0)
ax.contourf(y_grid_yz, z_grid_yz, counts_yz.T, zdir='x', offset=min(x), levels=50, cmap='Blues', zorder=0)