# -*- coding: utf-8 -*-

"""

绘制3d图形

"""

import matplotlib.pyplot as plt

import numpy as np

from mpl_toolkits.mplot3d import Axes3D

# 定义figure

fig = plt.figure()

# 将figure变为3d

ax = Axes3D(fig)

# 数据数目

n = 256

# 定义x, y

x = np.arange(-4, 4, 0.25)

y = np.arange(-4, 4, 0.25)

# 生成网格数据

X, Y = np.meshgrid(x, y)

# 计算每个点对的长度

R = np.sqrt(X ** 2 + Y ** 2)

# 计算Z轴的高度

Z = np.sin(R)

# 绘制3D曲面

ax.plot_surface(X, Y, Z, rstride = 1, cstride = 1, cmap = plt.get_cmap('rainbow'))

# 绘制从3D曲面到底部的投影

ax.contour(X, Y, Z, zdim = 'z', offset = -2, cmap = 'rainbow')

# 设置z轴的维度

ax.set_zlim(-2, 2)

plt.show()