tensor_function.h

// ---------------------------------------------------------------------
//
// Copyright (C) 1999 - 2017 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, redistribute
// it, and/or modify it under the terms of the GNU Lesser General
// Public License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// The full text of the license can be found in the file LICENSE at
// the top level of the deal.II distribution.
//
// ---------------------------------------------------------------------

#ifndef dealii_tensor_function_h
#define dealii_tensor_function_h


#include <deal.II/base/config.h>
#include <deal.II/base/exceptions.h>
#include <deal.II/base/subscriptor.h>
#include <deal.II/base/smartpointer.h>
#include <deal.II/base/function.h>
#include <deal.II/base/point.h>
#include <deal.II/base/function_time.h>

#include <vector>

DEAL_II_NAMESPACE_OPEN

template <int rank, int dim, typename Number=double>
class TensorFunction : public FunctionTime<Number>,
  public Subscriptor
{
public:
  typedef Tensor<rank,dim,Number> value_type;

  typedef Tensor<rank+1,dim,Number> gradient_type;

  TensorFunction (const Number initial_time = Number(0.0));

  virtual ~TensorFunction () = default;

  virtual value_type value (const Point<dim> &p) const;

  virtual void value_list (const std::vector<Point<dim> > &points,
                           std::vector<value_type> &values) const;

  virtual gradient_type gradient (const Point<dim> &p) const;

  virtual void gradient_list (const std::vector<Point<dim> >   &points,
                              std::vector<gradient_type> &gradients) const;
};



template <int rank, int dim, typename Number=double>
class ConstantTensorFunction : public TensorFunction<rank, dim, Number>
{
public:
  ConstantTensorFunction (const ::Tensor<rank, dim, Number> &value,
                          const Number initial_time = 0.0);

  virtual ~ConstantTensorFunction () = default;

  virtual typename ::TensorFunction<rank, dim, Number>::value_type value (const Point<dim> &p) const;

  virtual void value_list (const std::vector<Point<dim> > &points,
                           std::vector<typename ::TensorFunction<rank, dim, Number>::value_type> &values) const;

  virtual typename ::TensorFunction<rank, dim, Number>::gradient_type gradient (const Point<dim> &p) const;

  virtual void gradient_list (const std::vector<Point<dim> > &points,
                              std::vector<typename ::TensorFunction<rank, dim, Number>::gradient_type> &gradients) const;

private:
  const ::Tensor<rank, dim, Number> _value;
};



template <int rank, int dim, typename Number=double>
class ZeroTensorFunction : public ConstantTensorFunction<rank, dim, Number>
{
public:
  ZeroTensorFunction (const Number initial_time = 0.0);
};


DEAL_II_NAMESPACE_CLOSE

#endif