cgal-eigen-fitting-to2d

cgal-eigen-fitting-to2d.cpp

#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/linear_least_squares_fitting_3.h>
#include <vector>
#include <math.h>

typedef CGAL::Exact_predicates_inexact_constructions_kernel K;

typedef K::Plane_3                  Plane;
typedef K::Point_3                  Point3;

void cropz();

int main(void)
{
  std::vector< Point3 > lsPts;
  Point3 a(758731.86, 379196.97, 205.54);
  Point3 b(758736.08, 379207.34, 205.54);
  Point3 c(758743.72, 379204.23, 205.54);
  Point3 d(758739.37, 379193.92, 205.54);
  Point3 e(758732.25, 379196.81, 205.54);
  lsPts.push_back(a);
  lsPts.push_back(b);
  lsPts.push_back(c);
  lsPts.push_back(d);
  lsPts.push_back(e);

  //-- least-square plane
  Plane plane;
  linear_least_squares_fitting_3(lsPts.begin(), lsPts.end(), plane, CGAL::Dimension_tag<0>());  
  std::cout << "lq-plane= " << plane << std::endl;
  for (auto& pt : lsPts) {
    double dist = CGAL::squared_distance(pt, plane);
    std::cout << "dist= " << sqrt(dist) << std::endl;
  }

  std::cout << "Projection of points to the plane:" << std::endl;
  for (auto& p : lsPts) {
    K::Point_2 pt = plane.to_2d(p);
    std::cout << pt << std::endl;
  }

  std::cout << "============================" << std::endl;  

  cropz();

  return 0;
}


void cropz() {

  std::vector< Point3 > lsPts;
  Point3 a(758731.86, 379196.97, 5.54);
  Point3 b(758736.08, 379207.34, 5.54);
  Point3 c(758743.72, 379204.23, 5.54);
  Point3 d(758739.37, 379193.92, 5.54);
  Point3 e(758732.25, 379196.81, 5.54);
  lsPts.push_back(a);
  lsPts.push_back(b);
  lsPts.push_back(c);
  lsPts.push_back(d);
  lsPts.push_back(e);

  //-- least-square plane
  Plane plane;
  linear_least_squares_fitting_3(lsPts.begin(), lsPts.end(), plane, CGAL::Dimension_tag<0>());  
  std::cout << "lq-plane= " << plane << std::endl;
  for (auto& pt : lsPts) {
    double dist = CGAL::squared_distance(pt, plane);
    std::cout << "dist= " << sqrt(dist) << std::endl;
  }

  std::cout << "Projection of points to the plane:" << std::endl;
  for (auto& p : lsPts) {
    K::Point_2 pt = plane.to_2d(p);
    std::cout << pt << std::endl;
  }  

}