Constant.h

// Copyright (C) 2019 Chris Richardson and Michal Habera
//
// This file is part of DOLFINx (https://www.fenicsproject.org)
//
// SPDX-License-Identifier:    LGPL-3.0-or-later
 
#pragma once
 
#include <dolfinx/common/array2d.h>
#include <vector>
 
namespace dolfinx::fem
{
 
template <typename T>
class Constant
{
 
public:
  explicit Constant(T c) : value({c}) {}
 
  explicit Constant(const std::vector<T>& c) : shape(1, c.size()), value({c}) {}
 
  explicit Constant(const array2d<T>& c)
      : shape({(int)c.rows(), (int)c.cols()}), value(c.rows() * c.cols())
  {
    for (int i = 0; i < c.rows(); ++i)
      for (int j = 0; j < c.cols(); ++j)
        value[i * c.cols() + j] = c(i, j);
  }
 
  Constant(std::vector<int> shape, std::vector<T> value)
      : shape(shape), value(value)
  {
    // Do nothing
  }
 
  std::vector<int> shape;
 
  std::vector<T> value;
};
} // namespace dolfinx::fem