ref_line.hpp

// Copyright (C) 2025 Tiago V. L. Amorim (@tiagovla)
//
// This file is part of oiseau (https://github.com/tiagovla/oiseau)
//
// SPDX-License-Identifier: GPL-3.0-or-later
 
#pragma once
 
#include <xtensor/core/xtensor_forward.hpp>
 
#include "oiseau/dg/nodal/ref_element.hpp"
 
namespace oiseau::dg::nodal {

class RefLine : public RefElement {
 public:
  explicit RefLine(unsigned order);

  static xt::xarray<double> basis_function(const xt::xarray<double>& r, int i);

  static xt::xarray<double> grad_basis_function(const xt::xarray<double>& r, int i);
 
 private:
  xt::xarray<double> vandermonde(const xt::xarray<double>& r) const;

  xt::xarray<double> grad_vandermonde(const xt::xarray<double>& r) const;

  xt::xarray<double> grad_operator(const xt::xarray<double>& v, const xt::xarray<double>& gv) const;
};
 
namespace detail {

xt::xarray<double> generate_line_nodes(unsigned order);
 
}  // namespace detail
}  // namespace oiseau::dg::nodal