Function_Sm_in_Rd.h

/*    This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
 *    See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
 *    Author(s):       Siargey Kachanovich
 *
 *    Copyright (C) 2019 Inria
 *
 *    Modification(s):
 *      - YYYY/MM Author: Description of the modification
 */
 
#ifndef FUNCTIONS_FUNCTION_SM_IN_RD_H_
#define FUNCTIONS_FUNCTION_SM_IN_RD_H_
 
#include <cstdlib>  // for std::size_t
 
#include <Eigen/Dense>
 
namespace Gudhi {
 
namespace coxeter_triangulation {
 
struct Function_Sm_in_Rd {
  Eigen::VectorXd operator()(const Eigen::VectorXd& p) const {
    Eigen::VectorXd x = p;
    for (std::size_t i = 0; i < d_; ++i) x(i) -= center_[i];
    Eigen::VectorXd result = Eigen::VectorXd::Zero(k_);
    for (std::size_t i = 0; i < m_ + 1; ++i) result(0) += x(i) * x(i);
    result(0) -= r_ * r_;
    for (std::size_t j = 1; j < k_; ++j) result(j) = x(m_ + j);
    return result;
  }
 
  std::size_t amb_d() const { return d_; };
 
  std::size_t cod_d() const { return k_; };
 
  Eigen::VectorXd seed() const {
    Eigen::VectorXd result = Eigen::VectorXd::Zero(d_);
    result(0) += r_;
    for (std::size_t i = 0; i < d_; ++i) result(i) += center_[i];
    return result;
  }
 
  Function_Sm_in_Rd(double r, std::size_t m, std::size_t d, Eigen::VectorXd center)
      : m_(m), k_(d - m), d_(d), r_(r), center_(center) {}
 
  Function_Sm_in_Rd(double r, std::size_t m, std::size_t d)
      : m_(m), k_(d - m), d_(d), r_(r), center_(Eigen::VectorXd::Zero(d_)) {}
 
  Function_Sm_in_Rd(double r, std::size_t m, Eigen::VectorXd center)
      : m_(m), k_(1), d_(m_ + 1), r_(r), center_(center) {}
 
  Function_Sm_in_Rd(double r, std::size_t m) : m_(m), k_(1), d_(m_ + 1), r_(r), center_(Eigen::VectorXd::Zero(d_)) {}
 
  Function_Sm_in_Rd(const Function_Sm_in_Rd& rhs) : Function_Sm_in_Rd(rhs.r_, rhs.m_, rhs.d_, rhs.center_) {}
 
 private:
  std::size_t m_, k_, d_;
  double r_;
  Eigen::VectorXd center_;
};
 
}  // namespace coxeter_triangulation
 
}  // namespace Gudhi
 
#endif