pythonはmatplotlibを利用して3 D空間に平面を描くケースです。

import numpy as np
import matplotlib as mpl
from matplotlib import cm
from matplotlib import pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

#     
fig = plt.figure(figsize=(12, 8),
     facecolor='lightyellow'
    )
#    3D    
ax = fig.gca(fc='whitesmoke',
    projection='3d' 
   )#          
x = np.linspace(0, 9, 9)
y = np.linspace(0, 9, 9)
X, Y = np.meshgrid(x, y)
# --------------------------------    3D    --------------------------------
#    z=4.5    
ax.plot_surface(X,
    Y,
    Z=X*0+4.5,
    color='g',
    alpha=0.6
    ) 
 #    y=4.5    
ax.plot_surface(X,
    Y=X*0+4.5,
    Z=Y,
    color='y',
    alpha=0.6
    ) 
#    x=4.5    
ax.plot_surface(X=X*0+4.5,
    Y=Y,
    Z=X, 
    color='r',
    alpha=0.6
    ) 
# -------------------------------- --------------------------------
#           
ax.set(xlabel='X',
  ylabel='Y',
  zlabel='Z',
  xlim=(0, 9),
  ylim=(0, 9),
  zlim=(0, 9),
  xticks=np.arange(0, 10, 2),
  yticks=np.arange(0, 10, 1),
  zticks=np.arange(0, 10, 1)
  )
#     
ax.view_init(elev=15, #   
    azim=60 #    
   )
  
#     
plt.show()

#     
fig = plt.figure(figsize=(12, 8),
     facecolor='lightyellow'
    )
#    3D    
ax = fig.gca(fc='whitesmoke',
    projection='3d' 
   )
#        
x = np.linspace(0, 9, 9)
y = np.linspace(0, 9, 9)
X, Y = np.meshgrid(x, y)
# --------------------------------    3D    --------------------------------
#    z=3    
ax.plot_surface(X,
    Y,
    Z=X*0+3,
    color='g'
    )
#    z=2y    
ax.plot_surface(X,
    Y=Y,
    Z=Y*2,
    color='y',
    alpha=0.6
    )
#    z=-2y + 10   
ax.plot_surface(X=X,
    Y=Y,
    Z=-Y*2+10,
    color='r',
    alpha=0.7
    )
# -------------------------------- --------------------------------
#           
ax.set(xlabel='X',
  ylabel='Y',
  zlabel='Z',
  xlim=(0, 9),
  ylim=(0, 9),
  zlim=(0, 9),
  xticks=np.arange(0, 10, 2),
  yticks=np.arange(0, 10, 1),
  zticks=np.arange(0, 10, 1)
  )
#     
ax.view_init(elev=15, #   
    azim=10 #    
   )
  
#     
plt.show()

from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pylab as plt
import numpy as np
from matplotlib import cm
#  3d               
fig = plt.figure()
ax = fig.add_subplot(111,projection='3d')
"""numpy.linspace(start, stop, num=50, endpoint=True, retstep=False, dtype=None)
                。
meshgrid            ，          ，      x y   
"""
u = np.linspace(-1,1,100)
x,y =np.meshgrid(u,u)
z = x**2 +y**2
#        ，        
ax.plot_surface(x,y,z,rstride=4,cstride=4,cmap=cm.YlGnBu_r)
plt.show()