拟合平面代码
时间: 2023-07-02 18:07:08 浏览: 59
以下是拟合平面的代码示例:
```
import numpy as np
from numpy.linalg import lstsq
# 生成随机点
num_points = 100
X = np.random.rand(num_points, 3)
# 定义平面方程
a, b, c = 2, 3, -1
plane = a * X[:,0] + b * X[:,1] + c * X[:,2]
# 加入噪声
noise = 0.1*np.random.randn(num_points)
Y = plane + noise
# 拟合平面
A = np.c_[X[:,0], X[:,1], np.ones(num_points)]
result,_,_,_ = lstsq(A, Y)
# 输出结果
print('Coefficients:', result)
```
说明:
1. 首先生成了100个随机点 X,每个点有三个坐标,即 (x, y, z)。
2. 定义了平面方程 a*x + b*y + c*z,并将其应用于随机点 X 中,得到平面上的点。然后加入了一些噪声,使数据更加真实。
3. 使用最小二乘法拟合平面,得到平面方程系数。
4. 输出结果。
相关问题
CGAL Ransac拟合平面代码
下面是使用CGAL库实现RANSAC拟合平面的示例代码:
```c++
#include <iostream>
#include <cstdlib>
#include <vector>
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Plane_3.h>
#include <CGAL/Random.h>
#include <CGAL/algorithm.h>
#include <CGAL/point_generators_3.h>
#include <CGAL/Timer.h>
typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;
typedef Kernel::Point_3 Point_3;
typedef Kernel::Plane_3 Plane_3;
int main(int argc, char* argv[])
{
// Generate random points
int num_points = 1000000;
std::vector<Point_3> points;
points.reserve(num_points);
CGAL::Random rand(42);
std::cout << "Generating " << num_points << " random points..." << std::endl;
CGAL::Timer timer;
timer.start();
CGAL::Random_points_in_cube_3<Point_3> gen(1.0);
for (int i = 0; i < num_points; ++i)
points.push_back(*gen++);
timer.stop();
std::cout << "Time to generate points: " << timer.time() << " seconds" << std::endl;
// Set up RANSAC parameters
double threshold = 0.1; // maximum distance from point to plane to be considered an inlier
int max_iterations = 1000; // maximum number of iterations to run RANSAC
int min_inliers = 100; // minimum number of inliers to consider the result valid
// Run RANSAC
std::cout << "Running RANSAC..." << std::endl;
timer.reset();
timer.start();
Plane_3 best_fit;
int best_num_inliers = 0;
for (int i = 0; i < max_iterations; ++i)
{
// Select three random points
std::vector<Point_3> sample;
for (int j = 0; j < 3; ++j)
sample.push_back(points[rand.get_int(0, num_points-1)]);
// Fit plane to sample
Plane_3 plane(sample[0], sample[1], sample[2]);
// Count inliers
int num_inliers = 0;
for (int j = 0; j < num_points; ++j)
{
if (CGAL::squared_distance(points[j], plane) < threshold*threshold)
++num_inliers;
}
// Update best fit if this one is better
if (num_inliers > best_num_inliers)
{
best_fit = plane;
best_num_inliers = num_inliers;
}
// Stop early if we have enough inliers
if (best_num_inliers >= min_inliers)
break;
}
timer.stop();
std::cout << "Time to run RANSAC: " << timer.time() << " seconds" << std::endl;
// Output result
std::cout << "Best fit plane: " << best_fit << std::endl;
std::cout << "Number of inliers: " << best_num_inliers << std::endl;
return 0;
}
```
该代码生成了一百万个随机点,然后使用RANSAC算法拟合平面,并输出最佳拟合平面及其所包含的内点数。您可以根据需要修改代码以适应自己的应用场景。
matlab平面拟合代码
下面是一个用MATLAB进行平面拟合的代码示例:
```matlab
clear all;
close all;
% 随机生成一组(x,y,z)这些点的坐标离一个平面比较近
x0=1;
L1=2;
y0=1;
L2=2;
x=x0+rand(20,1)*L1;
y=y0+rand(20,1)*L2;
z=1+2*x+3*y;
scatter3(x,y,z,'filled')
hold on;
data=[x,y,z];
x=data(:,1);
y=data(:,2);
z=data(:,3);
% 平方的均值
x_a=sum(x)/length(data);
y_a=sum(y)/length(data);
z_a=sum(z)/length(data);
xx_a=sum(x.*x)/length(data);
yy_a=sum(y.*y)/length(data);
zz_a=sum(z.*z)/length(data);
xy_a=sum(x.*y)/length(data);
xz_a=sum(x.*z)/length(data);
yz_a=sum(y.*z)/length(data);
% 方程组的系数矩阵
A=[xx_a xy_a x_a; xy_a yy_a y_a; x_a y_a 1];
b=[xz_a;yz_a;z_a];
XYZ=A^-1 *b;
% 方程求系数
a0=XYZ(1); % -A/C
a1=XYZ(2); % -B/C
a2=XYZ(3); % -D/C
V=[a0 a1 -1];% 平面法向量
nor=norm(V); % 向量的模
normalize_V=[a0/nor a2/nor -1/nor]; % 平面法向量归一化
% 开始绘制图像
scatter3(x,y,z,'filled')
hold on;
xfit=min(x):0.1:max(x); % 坐标系的坐标
yfit=min(y):0.1:max(y);
[XF,YF]=meshgrid(xfit,yfit);% 生产XY点列
ZF=a0*XF+a1*YF+a2; %计算Z的值
% 显示
mesh(XF,YF,ZF)
```
这段代码使用最小二乘法来拟合一个平面,其中从给定的点集中计算出平面方程的系数,并根据这个方程绘制平面拟合图形。