/usr/include/dolfin/la/VectorSpaceBasis.h is in libdolfin-dev 2016.2.0-2.
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 | // Copyright (C) 2013 Patrick E. Farrell
//
// 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: 2013-05-29
// Last changed: 2013-05-29
#ifndef __VECTOR_SPACE_BASIS_H
#define __VECTOR_SPACE_BASIS_H
#include <memory>
#include <vector>
namespace dolfin
{
class GenericVector;
/// This class defines a basis for vector spaces,
/// typically used for expressing nullspaces, transpose nullspaces
/// and near nullspaces of singular operators
class VectorSpaceBasis
{
public:
/// Constructor
VectorSpaceBasis(const std::vector<std::shared_ptr<GenericVector>> basis);
/// Destructor
~VectorSpaceBasis() {}
/// Apply the Gram-Schmidt process to orthonormalize the
/// basis. Throws an error if a (near) linear dependency is
/// detected. Error is thrown if <x_i, x_i> < tol.
void orthonormalize(double tol=1.0e-10);
/// Test if basis is orthonormal
bool is_orthonormal(double tol=1.0e-10) const;
/// Test if basis is orthogonal
bool is_orthogonal(double tol=1.0e-10) const;
/// Orthogonalize x with respect to basis
void orthogonalize(GenericVector& x) const;
/// Number of vectors in the basis
std::size_t dim() const;
/// Get a particular basis vector
std::shared_ptr<const GenericVector> operator[] (std::size_t i) const;
private:
// Basis vectors
const std::vector<std::shared_ptr<GenericVector>> _basis;
};
}
#endif
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