#coding: utf-8

import matplotlib.pyplot as plt

import numpy as np

from matplotlib import cm

from matplotlib.ticker import LinearLocator, FormatStrFormatter

from mpl_toolkits.mplot3d import Axes3D

# 绘制3D梯度下降图

def d3_hookface():

fig = plt.figure() # 得到画面

ax = fig.gca(projection='3d') # 得到3d坐标的图

X = np.arange(-5, 5, 0.1)

Y = np.arange(-5, 5, 0.1)

X,Y = np.meshgrid(X, Y) # 将坐标向量变为坐标矩阵，列为x的长度，行为y的长度

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

Z = np.sin(R)

# 曲面，x,y,z坐标，横向步长，纵向步长，颜色，线宽，是否渐变

surf = ax.plot_surface(X, Y, Z, rstride=1, cstride=1, cmap=cm.coolwarm, linewidth=0, antialiased=False)

ax.set_zlim(-1.01, 1.01)

ax.set_xlabel("x-label", color='r')

ax.set_ylabel("y-label", color='g')

ax.set_zlabel("z-label", color='b')

ax.zaxis.set_major_locator(LinearLocator(10)) # 设置z轴标度

ax.zaxis.set_major_formatter(FormatStrFormatter('%0.02f')) # 设置z轴精度

# shrink颜色条伸缩比例0-1, aspect颜色条宽度（反比例，数值越大宽度越窄）

fig.colorbar(surf, shrink=0.5, aspect=5)

plt.savefig("d3_hookface.png")

plt.show()

def d3_scatter():

fig = plt.figure()

ax = fig.add_subplot(111, projection='3d')

n = 50

# For each set of style and range settings, plot n random points in the box

# defined by x in [23, 32], y in [0, 100], z in [zlow, zhigh].

for c, m, zlow, zhigh in [('r', 'o', -50, -25), ('g', '+', -20, 15),('b', '^', -30, -5)]:

xs = randrange(n, 23, 32)

ys = randrange(n, 0, 100)

zs = randrange(n, zlow, zhigh)

ax.scatter(xs, ys, zs, c=c, marker=m)

ax.set_xlabel('X Label')

ax.set_ylabel('Y Label')

ax.set_zlabel('Z Label')

plt.show()

def randrange(n, vmin, vmax):

return (vmax - vmin) * np.random.rand(n) + vmin

if __name__ =='__main__':

# 绘制3D梯度下降图

# d3_hookface()

# 绘制3D散点图

d3_scatter()