python实现三维拟合的方法_Python

python实现三维拟合的方法

2021-05-09 00:41changye777 Python

今天小编就为大家分享一篇python实现三维拟合的方法，具有很好的参考价值，希望对大家有所帮助。一起跟随小编过来看看吧

如下所示：

				?

									from matplotlib import pyplot as plt

									import numpy as np

									from mpl_toolkits.mplot3d import Axes3D

									fig = plt.figure()

									ax = Axes3D(fig)

									#列出实验数据

									point=[[2,3,48],[4,5,50],[5,7,51],[8,9,55],[9,12,56]]

									plt.xlabel("X1")

									plt.ylabel("X2")

									#表示矩阵中的值

									ISum = 0.0

									X1Sum = 0.0

									X2Sum = 0.0

									X1_2Sum = 0.0

									X1X2Sum = 0.0

									X2_2Sum = 0.0

									YSum = 0.0

									X1YSum = 0.0

									X2YSum = 0.0

									#在图中显示各点的位置

									for i in range(0,len(point)):

									 x1i=point[i][0]

									 x2i=point[i][1]

									 yi=point[i][2]

									 ax.scatter(x1i, x2i, yi, color="red")

									 show_point = "["+ str(x1i) +","+ str(x2i)+","+str(yi) + "]"

									 ax.text(x1i,x2i,yi,show_point)

									 ISum = ISum+1

									 X1Sum = X1Sum+x1i

									 X2Sum = X2Sum+x2i

									 X1_2Sum = X1_2Sum+x1i**2

									 X1X2Sum = X1X2Sum+x1i*x2i

									 X2_2Sum = X2_2Sum+x2i**2

									 YSum = YSum+yi

									 X1YSum = X1YSum+x1i*yi

									 X2YSum = X2YSum+x2i*yi

									# 进行矩阵运算

									# _mat1 设为 mat1 的逆矩阵

									m1=[[ISum,X1Sum,X2Sum],[X1Sum,X1_2Sum,X1X2Sum],[X2Sum,X1X2Sum,X2_2Sum]]

									mat1 = np.matrix(m1)

									m2=[[YSum],[X1YSum],[X2YSum]]

									mat2 = np.matrix(m2)

									_mat1 =mat1.getI()

									mat3 = _mat1*mat2

									# 用list来提取矩阵数据

									m3=mat3.tolist()

									a0 = m3[0][0]

									a1 = m3[1][0]

									a2 = m3[2][0]

									# 绘制回归线

									x1 = np.linspace(0,9)

									x2 = np.linspace(0,12)

									y = a0+a1*x1+a2*x2

									ax.plot(x1,x2,y)

									show_line = "y="+str(a0)+"+"+str(a1)+"x1"+"+"+str(a2)+"x2"

									plt.title(show_line)

									plt.show()