/usr/include/dolfin/la/LinearOperator.h is in libdolfin-dev 2017.2.0.post0-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 | // Copyright (C) 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/>.
//
// First added: 2012-08-20
// Last changed: 2012-12-12
#ifndef __LINEAR_OPERATOR_H
#define __LINEAR_OPERATOR_H
#include <memory>
#include <dolfin/common/MPI.h>
#include "GenericLinearOperator.h"
namespace dolfin
{
/// This class defines an interface for linear operators defined
/// only in terms of their action (matrix-vector product) and can be
/// used for matrix-free solution of linear systems. The linear
/// algebra backend is decided at run-time based on the present
/// value of the "linear_algebra_backend" parameter.
///
/// To define a linear operator, users need to inherit from this
/// class and overload the function mult(x, y) which defines the
/// action of the matrix on the vector x as y = Ax.
///
class LinearOperator : public GenericLinearOperator
{
public:
/// Create linear operator
LinearOperator();
/// Create linear operator to match parallel layout of vectors
/// x and y for product y = Ax.
LinearOperator(const GenericVector& x, const GenericVector& y);
/// Destructor
virtual ~LinearOperator() {}
/// Return size of given dimension
virtual std::size_t size(std::size_t dim) const = 0;
/// Compute matrix-vector product y = Ax
virtual void mult(const GenericVector& x, GenericVector& y) const = 0;
/// Return the MPI communicator
virtual MPI_Comm mpi_comm() const
{ dolfin_assert(_matA); return _matA->mpi_comm(); }
/// Return informal string representation (pretty-print)
std::string str(bool verbose) const;
//--- Special functions, intended for library use only ---
/// Return concrete instance / unwrap (const version)
virtual const GenericLinearOperator* instance() const;
/// Return concrete instance / unwrap (non-const version)
virtual GenericLinearOperator* instance();
/// Return concrete instance / unwrap (const shared pointer version)
virtual std::shared_ptr<const LinearAlgebraObject> shared_instance() const;
/// Return concrete instance / unwrap (shared pointer version)
virtual std::shared_ptr<LinearAlgebraObject> shared_instance();
private:
// Pointer to concrete implementation
std::shared_ptr<GenericLinearOperator> _matA;
};
}
#endif
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