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Diffstat (limited to 'src/Coxeter_triangulation/include/gudhi/Functions/Function_moment_curve_in_Rd.h')
-rw-r--r-- | src/Coxeter_triangulation/include/gudhi/Functions/Function_moment_curve_in_Rd.h | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/src/Coxeter_triangulation/include/gudhi/Functions/Function_moment_curve_in_Rd.h b/src/Coxeter_triangulation/include/gudhi/Functions/Function_moment_curve_in_Rd.h new file mode 100644 index 00000000..91eb016b --- /dev/null +++ b/src/Coxeter_triangulation/include/gudhi/Functions/Function_moment_curve_in_Rd.h @@ -0,0 +1,89 @@ +/* This file is part of the Gudhi Library. The Gudhi library + * (Geometric Understanding in Higher Dimensions) is a generic C++ + * library for computational topology. + * + * Author(s): Siargey Kachanovich + * + * Copyright (C) 2019 Inria + * + * Modification(s): + * - YYYY/MM Author: Description of the modification + */ + +#ifndef FUNCTIONS_FUNCTION_MOMENT_CURVE_IN_RD_H_ +#define FUNCTIONS_FUNCTION_MOMENT_CURVE_IN_RD_H_ + +#include <gudhi/Functions/Function.h> +#include <Eigen/Dense> + +namespace Gudhi { + +namespace coxeter_triangulation { + +/** + * \class Function_moment_curve_in_Rd + * \brief A class for the function that defines an implicit moment curve + * in the d-dimensional Euclidean space. + * + * \ingroup coxeter_triangulation + */ +struct Function_moment_curve_in_Rd : public Function { + +/** \brief Value of the function at a specified point. + * @param[in] p The input point. The dimension needs to coincide with the ambient dimension. + */ + Eigen::VectorXd operator()(const Eigen::VectorXd& p) const { + Eigen::VectorXd result(k_); + for (std::size_t i = 1; i < d_; ++i) + result(i-1) = p(i) - p(0) * p(i-1); + return result; + } + + /** \brief Returns the domain (ambient) dimension.. */ + std::size_t amb_d() const {return d_;}; + + /** \brief Returns the codomain dimension. */ + std::size_t cod_d() const {return k_;}; + + /** \brief Returns a point on the moment curve. */ + Eigen::VectorXd seed() const { + Eigen::VectorXd result = Eigen::VectorXd::Zero(d_); + return result; + } + + /** + * \brief Constructor of the function that defines an implicit moment curve + * in the d-dimensional Euclidean space. + * + * @param[in] r Numerical parameter. + * @param[in] d The ambient dimension. + */ + Function_moment_curve_in_Rd(double r, + std::size_t d) + : m_(1), k_(d-1), d_(d), r_(r) {} + + /** + * \brief Constructor of the function that defines an implicit moment curve + * in the d-dimensional Euclidean space. + * + * @param[in] r Numerical parameter. + * @param[in] d The ambient dimension. + * @param[in] offset The offset of the moment curve. + */ + Function_moment_curve_in_Rd(double r, + std::size_t d, + Eigen::VectorXd& offset) + : m_(1), k_(d-1), d_(d), r_(r), off_(offset) {} + +protected: + std::size_t m_, k_, d_; + double r_; + Eigen::VectorXd off_; +}; + +} // namespace coxeter_triangulation + +} // namespace Gudhi + + +#endif |