Ejemplo n.º 1
0
void
NurbsTools::pca (const vector_vec2d &data, Eigen::Vector2d &mean, Eigen::Matrix2d &eigenvectors,
                 Eigen::Vector2d &eigenvalues)
{
  if (data.empty ())
  {
    printf ("[NurbsTools::pca] Error, data is empty\n");
    abort ();
  }

  mean = computeMean (data);

  unsigned s = unsigned (data.size ());

  Eigen::MatrixXd Q (2, s);

  for (unsigned i = 0; i < s; i++)
    Q.col (i) << (data[i] - mean);

  Eigen::Matrix2d C = Q * Q.transpose ();

  Eigen::SelfAdjointEigenSolver<Eigen::Matrix2d> eigensolver (C);
  if (eigensolver.info () != Success)
  {
    printf ("[NurbsTools::pca] Can not find eigenvalues.\n");
    abort ();
  }

  for (int i = 0; i < 2; ++i)
  {
    eigenvalues (i) = eigensolver.eigenvalues () (1 - i);
    eigenvectors.col (i) = eigensolver.eigenvectors ().col (1 - i);
  }
}
Ejemplo n.º 2
0
	void Triangle::setJac(){
	    Eigen::Matrix2d J;
	    J.col(0) = (M_points[1]-M_points[0]).toEig();
	    J.col(1) = (M_points[2]-M_points[0]).toEig();
	    M_jac = J;
	}