python - MatPlotLib plot_surface : hidden lines appearing in PDF

Question

我正在使用 MatPlotLib 的 plot_surface 方法生成 3D 表面，然后将其保存为 PDF 文件。我可以通过“linewidth=0”隐藏表面线条，但在保存为 PDF 后线条再次出现。

编辑:当对 .png 和 .svg 执行 savefig() 时，隐藏线保持隐藏状态。

下图第一张是plt.show()结果截图，第二张是PDF结果截图。关于如何使 PDF 中的隐藏线不可见，我有什么想法吗？

我会把代码贴在底部，因为它有点长。 Windows 7(64 位)、Python 2.7.3 (win32)、MatPlotLib 1.2.0 (win32)。

改变计划，这个论坛不允许我发图片，一些关于没有声誉的事情:)。所以只写代码。

#=====================================================================

# get external packages
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

#=====================================================================

Gw1 = plt.figure("Sphere-Cylinder Intersection")
diagram1 = Axes3D(Gw1)
diagram1.view_init(33,-48)

# force equal aspect ratio in all 3 directions
# 3D library is missing this -- force it with an invisible bounding cube
diagram1.set_aspect('equal')
CUBE = 1.3
for direction in (-1, 1):
    for point in np.diag(direction * CUBE * np.array([1,1,1])):
        diagram1.plot([point[0]], [point[1]], [point[2]], 'white')

# line for y-axis (show as N/E/D coords, not plotting coords)
diagram1.plot([0.0,1.5],[0.0,0.0],[0.0,0.0],
              linewidth=1,linestyle='-',color='black')
diagram1.text(1.6,0.0,0.0,'y',fontsize=14,fontweight='bold')

# line for x-axis (show as N/E/D coords, not plotting coords)
diagram1.plot([0.0,0.0],[0.0,1.5],[0.0,0.0],
              linewidth=1,linestyle='-',color='black')
diagram1.text(0.0,1.6,0.0,'x',fontsize=14,fontweight='bold')

# line for z-axis (show as N/E/D coords, not plotting coords)
diagram1.plot([0.0,0.0],[0.0,0.0],[0.0,-1.5],
              linewidth=1,linestyle='-',color='black')
diagram1.text(0.0,0.0,-1.7,'z',fontsize=14,fontweight='bold')

# unit sphere about origin
phi = np.linspace(0.0,np.pi/2.0,361)
theta = np.linspace(0.0,np.pi,361)
phi,theta = np.meshgrid(phi,theta)
x = np.sin(theta)*np.cos(phi)
y = np.sin(theta)*np.sin(phi)
z = np.cos(theta)
diagram1.plot_surface(x,y,z,linewidth=0.0,color='DarkKhaki',alpha=0.25)

# elliptical cylinder about z-axis 1
a = 0.10
b = 0.15
x = a*np.cos(np.linspace(0.0,np.pi/2.0,101))
z = np.linspace(-1.3,1.3,101)
x,z = np.meshgrid(x,z)
y = b*np.sin(np.arccos(x/a))
diagram1.plot_surface(x,y,z,linewidth=0.0,color='red',alpha=0.25)

# elliptical cylinder about z-axis 2
a = 0.21
b = 0.315
x = a*np.cos(np.linspace(0.0,np.pi/2.0,101))
z = np.linspace(-1.3,1.3,101)
x,z = np.meshgrid(x,z)
y = b*np.sin(np.arccos(x/a))
diagram1.plot_surface(x,y,z,linewidth=0.0,color='red',alpha=0.25)

# elliptical cylinder about z-axis 3
a = 0.42
b = 0.63
x = a*np.cos(np.linspace(0.0,np.pi/2.0,101))
z = np.linspace(-1.3,1.3,101)
x,z = np.meshgrid(x,z)
y = b*np.sin(np.arccos(x/a))
diagram1.plot_surface(x,y,z,linewidth=0.0,color='red',alpha=0.25)

# sphere-cylinder intersection 1
a = 0.10
b = 0.15
x = a*np.cos(np.linspace(0.0,np.pi/2.0,101))
y = b*np.sin(np.linspace(0.0,np.pi/2.0,101))
z = np.sqrt(np.around(1.0-x**2-y**2,decimals=10))
diagram1.plot(x,y,z,linewidth=1.0,linestyle='-',color='red')
diagram1.plot(x,y,-z,linewidth=1.0,linestyle='-',color='red')

# sphere-cylinder intersection 2
a = 0.21
b = 0.315
x = a*np.cos(np.linspace(0.0,np.pi/2.0,101))
y = b*np.sin(np.linspace(0.0,np.pi/2.0,101))
z = np.sqrt(np.around(1.0-x**2-y**2,decimals=10))
diagram1.plot(x,y,z,linewidth=1.0,linestyle='-',color='red')
diagram1.plot(x,y,-z,linewidth=1.0,linestyle='-',color='red')

# sphere-cylinder intersection 3
a = 0.42
b = 0.63
x = a*np.cos(np.linspace(0.0,np.pi/2.0,101))
y = b*np.sin(np.linspace(0.0,np.pi/2.0,101))
z = np.sqrt(np.around(1.0-x**2-y**2,decimals=10))
diagram1.plot(x,y,z,linewidth=1.0,linestyle='-',color='red')
diagram1.plot(x,y,-z,linewidth=1.0,linestyle='-',color='red')

# plotting axes off
diagram1.axis('off')

# display/save
plt.savefig ("Diagram1.pdf")
plt.show()

#=====================================================================

Answer 1

正如 esmit 所建议的，输出在其他图像格式(PNG 和 SVG)中似乎是正确的这一事实表明 PDF 后端可能存在错误。我将在 github 上发布错误报告。

感谢您的提示!