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Diffstat (limited to 'src/Coxeter_triangulation/include/gudhi/Functions/Constant_function.h')
-rw-r--r-- | src/Coxeter_triangulation/include/gudhi/Functions/Constant_function.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/src/Coxeter_triangulation/include/gudhi/Functions/Constant_function.h b/src/Coxeter_triangulation/include/gudhi/Functions/Constant_function.h new file mode 100644 index 00000000..0603afd8 --- /dev/null +++ b/src/Coxeter_triangulation/include/gudhi/Functions/Constant_function.h @@ -0,0 +1,64 @@ +/* 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_CONSTANT_FUNCTION_H_ +#define FUNCTIONS_CONSTANT_FUNCTION_H_ + +#include <cstdlib> // for std::size_t + +#include <Eigen/Dense> + +namespace Gudhi { + +namespace coxeter_triangulation { + +/** + * \class Constant_function + * \brief A class that encodes a constant function from R^d to R^k. + * This class does not have any implicit manifold in correspondence. + */ +struct Constant_function { + /** \brief Value of the function at a specified point. The value is constant. + * @param[in] p The input point. The dimension needs to coincide with the ambient dimension. + */ + Eigen::VectorXd operator()(const Eigen::VectorXd& p) const { + return value_; + } + + /** \brief Returns the domain dimension. Same as the ambient dimension of the sphere. */ + std::size_t amb_d() const { return d_; }; + + /** \brief Returns the codomain dimension. Same as the codimension of the sphere. */ + std::size_t cod_d() const { return k_; }; + + /** \brief No seed point is available. Throws an exception on evocation. */ + Eigen::VectorXd seed() const { throw "Seed invoked on a constant function.\n"; } + + Constant_function() {} + + /** + * \brief Constructor of a constant function from R^d to R^m. + * + * @param[in] d The domain dimension. + * @param[in] k The codomain dimension. + * @param[in] value The constant value of the function. + */ + Constant_function(std::size_t d, std::size_t k, const Eigen::VectorXd& value) : d_(d), k_(k), value_(value) {} + + private: + std::size_t d_, k_; + Eigen::VectorXd value_; +}; + +} // namespace coxeter_triangulation + +} // namespace Gudhi + +#endif |