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

fig = plt.figure(figsize=(9,6),
         facecolor='khaki'
        )
ax = fig.gca(projection='3d')
# 二元函数定义域平面集
x = np.linspace(start=-3,
        stop=3,
        num=100
        )
y = np.linspace(start=-3,
        stop=3,
        num=100
        )
X, Y = np.meshgrid(x, y)  # 网格数据
Z = np.power(X, 2) + np.power(Y, 2)  # 二元函数 z = x**2 + y**2
# 绘图
surf = ax.plot_surface(X=X,
            Y=Y,
            Z=Z,
            rstride=2,  # row stride, 行跨度
            cstride=2,  # column stride, 列跨度 
            color='r',
            linewidth=0.5,
           )
# 调整视角
ax.view_init(elev=7,  # 仰角
       azim=30  # 方位角
      )
# 显示图形
plt.show()

fig = plt.figure(figsize=(9,6),
         facecolor='khaki'
        )
ax = fig.gca(projection='3d')
# 二元函数定义域平面集
x = np.linspace(start=-3,
        stop=3,
        num=100
        )
y = np.linspace(start=-3,
        stop=3,
        num=100
        )
X, Y = np.meshgrid(x, y)  # 网格数据
Z = np.power(X, 2) + np.power(Y, 2)  # 二元函数 z = x**2 + y**2
# 绘图
surf = ax.plot_surface(X=X,
            Y=Y,
            Z=-Z,
            rstride=2,  # row stride, 行跨度
            cstride=2,  # column stride, 列跨度 
            color='g',
            linewidth=0.5,
           )
# 调整视角
ax.view_init(elev=7,  # 仰角
       azim=30  # 方位角
      )
# 显示图形
plt.show()

fig = plt.figure(figsize=(24, 16),
         facecolor='khaki'
        )
# 二元函数定义域平面集
x = np.linspace(start=-3,
        stop=3,
        num=100
        )
y = np.linspace(start=-3,
        stop=3,
        num=100
        )
X, Y = np.meshgrid(x, y)  # 网格数据
Z = np.power(X, 2) + np.power(Y, 2)  # 二元函数 z = x**2 + y**2
# -------------------------------- subplot(221) --------------------------------
ax = fig.add_subplot(221, projection='3d')
# 开口向上的抛物面
surf = ax.plot_surface(X=X,
            Y=Y,
            Z=Z,
            rstride=2,  # row stride, 行跨度
            cstride=2,  # column stride, 列跨度 
            color='r',
            linewidth=0.5,
           )
# -------------------------------- subplot(223) --------------------------------
ax = fig.add_subplot(223, projection='3d')
# 开口向下的抛物面
surf = ax.plot_surface(X=X,
            Y=Y,
            Z=-Z,
            rstride=2,  # row stride, 行跨度
            cstride=2,  # column stride, 列跨度 
            color='g',
            linewidth=0.5,
           )
# -------------------------------- subplot(22, (2,4)) --------------------------------
ax = plt.subplot2grid(shape=(2,2),
           loc=(0, 1),
           rowspan=2,
           projection='3d'
           )
# 开口向上的抛物面
surf1 = ax.plot_surface(X=X,
            Y=Y,
            Z=Z,
            rstride=2,  # row stride, 行跨度
            cstride=2,  # column stride, 列跨度 
            color='r',
            linewidth=0.5,
            )
# 开口向下的抛物面
surf2 = ax.plot_surface(X=X,
            Y=Y,
            Z=-Z,
            rstride=2,  # row stride, 行跨度
            cstride=2,  # column stride, 列跨度 
            color='g',
            linewidth=0.5,
           )
# 调整视角
ax.view_init(elev=7,  # 仰角
       azim=30  # 方位角
      )
# -------------------------------- fig --------------------------------
# 调整子区布局
fig.subplots_adjust(wspace=0.1,  # width space
          hspace=0.15  # height space
          )
# 显示图形
plt.show()