Function.h

// Copyright (C) 2003-2012 Anders Logg
//
// This file is part of DOLFIN.
//
// DOLFIN is free software: you can 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 3 of the License, or
// (at your option) any later version.
//
// DOLFIN is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with DOLFIN. If not, see <http://www.gnu.org/licenses/>.
//
// Modified by Garth N. Wells, 2005-2010.
// Modified by Kristian B. Oelgaard, 2007.
// Modified by Martin Sandve Alnes, 2008-2014.
// Modified by Andre Massing, 2009.

#ifndef __FUNCTION_H
#define __FUNCTION_H

#include <memory>
#include <string>
#include <utility>
#include <vector>
#include <boost/ptr_container/ptr_map.hpp>
#include <Eigen/Dense>

#include <dolfin/common/types.h>
#include <dolfin/common/Hierarchical.h>
#include "GenericFunction.h"
#include "FunctionAXPY.h"

namespace ufc
{
  // Forward declarations
  class cell;
}

namespace dolfin
{

  // Forward declarations
  class Cell;
  class Expression;
  class FunctionSpace;
  class GenericVector;
  class SubDomain;
  template<typename T> class Array;


  class Function : public GenericFunction, public Hierarchical<Function>
  {
  public:

    Function() : Hierarchical<Function>(*this) {}

    explicit Function(std::shared_ptr<const FunctionSpace> V);

    Function(std::shared_ptr<const FunctionSpace> V,
             std::shared_ptr<GenericVector> x);

    Function(std::shared_ptr<const FunctionSpace> V,
             std::string filename);

    Function(const Function& v);

    Function(const Function& v, std::size_t i);

    virtual ~Function();

    const Function& operator= (const Function& v);

    const Function& operator= (const Expression& v);

    void operator=(const FunctionAXPY& axpy);

    Function& operator[] (std::size_t i) const;

    virtual std::shared_ptr<const FunctionSpace> function_space() const override
    {
      dolfin_assert(_function_space);
      return _function_space;
    }

    std::shared_ptr<GenericVector> vector();

    std::shared_ptr<const GenericVector> vector() const;

    bool in(const FunctionSpace& V) const;

    std::size_t geometric_dimension() const;

    void eval(Array<double>& values, const Array<double>& x) const override;

    void eval(Array<double>& values, const Array<double>& x,
              const Cell& dolfin_cell, const ufc::cell& ufc_cell) const;

    void eval(Eigen::Ref<Eigen::VectorXd> values,
              Eigen::Ref<const Eigen::VectorXd> x) const override;

    void eval(Eigen::Ref<Eigen::VectorXd> values,
              Eigen::Ref<const Eigen::VectorXd> x,
              const dolfin::Cell& dolfin_cell, const ufc::cell& ufc_cell) const;

    void interpolate(const GenericFunction& v);

    void extrapolate(const Function& v);

    //--- Implementation of GenericFunction interface ---

    virtual std::size_t value_rank() const override;

    virtual std::size_t value_dimension(std::size_t i) const override;

    virtual std::vector<std::size_t> value_shape() const override;

    virtual void eval(Array<double>& values, const Array<double>& x,
                      const ufc::cell& cell) const override;

    virtual void eval(Eigen::Ref<Eigen::VectorXd> values,
                      Eigen::Ref<const Eigen::VectorXd> x,
                      const ufc::cell& cell) const override;

    virtual void restrict(double* w,
                          const FiniteElement& element,
                          const Cell& dolfin_cell,
                          const double* coordinate_dofs,
                          const ufc::cell& ufc_cell) const override;

    virtual void compute_vertex_values(std::vector<double>& vertex_values,
                                       const Mesh& mesh) const override;

    void compute_vertex_values(std::vector<double>& vertex_values);

    void set_allow_extrapolation(bool allow_extrapolation)
    { _allow_extrapolation = allow_extrapolation; }

    bool get_allow_extrapolation() const
    { return _allow_extrapolation; }

  private:

    // Friends
    friend class FunctionSpace;
    friend class FunctionAssigner;

    // Collection of sub-functions which share data with the function
    mutable boost::ptr_map<std::size_t, Function> _sub_functions;

    // Initialize vector
    void init_vector();

    // The function space
    std::shared_ptr<const FunctionSpace> _function_space;

    // The vector of expansion coefficients (local)
    std::shared_ptr<GenericVector> _vector;

    // True if extrapolation should be allowed
    bool _allow_extrapolation;

  };

}

#endif