Principal_component_analysis/centroid.cpp

// Example program for the centroid() function for 2D points, 3D points and 3D triangles.

#include <CGAL/Simple_cartesian.h>
#include <CGAL/centroid.h>

#include <vector>
#include <iostream>

typedef double                      FT;
typedef CGAL::Simple_cartesian<FT>  K;
typedef K::Point_2                  Point_2;
typedef K::Point_3                  Point_3;
typedef K::Triangle_3               Triangle_3;

int main()
{
  // centroid of 2D points
  std::vector<Point_2> points_2;
  points_2.push_back(Point_2(1.0, 0.0));
  points_2.push_back(Point_2(2.0, 2.0));
  points_2.push_back(Point_2(3.0, 5.0));
  Point_2 c2 = CGAL::centroid(points_2.begin(), points_2.end(),CGAL::Dimension_tag<0>());
  std::cout << c2 << std::endl;

  // centroid of 3D points
  std::vector<Point_3> points_3;
  points_3.push_back(Point_3(1.0, 0.0, 0.5));
  points_3.push_back(Point_3(2.0, 2.0, 1.2));
  points_3.push_back(Point_3(3.0, 5.0, 4.5));
  Point_3 c3 = CGAL::centroid(points_3.begin(), points_3.end(),CGAL::Dimension_tag<0>());
  std::cout << c3 << std::endl;

  // centroid of 3D triangles
  std::list<Triangle_3> triangles_3;
  Point_3 p(1.0, 0.0, 0.0);
  Point_3 q(1.0, 2.0, 0.0);
  Point_3 r(0.0, 1.0, 3.0);
  Point_3 s(0.0, 2.0, 5.0);
  triangles_3.push_back(Triangle_3(p,q,r));
  triangles_3.push_back(Triangle_3(p,q,s));
  c3 = CGAL::centroid(triangles_3.begin(), triangles_3.end(),CGAL::Dimension_tag<2>());
  std::cout << c3 << std::endl;

  return 0;
}