/usr/include/rheolef/ublas-invert.h is in librheolef-dev 6.7-6.
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 91 92 93 | #ifndef _RHEOLEF_UBLAS_INVERT_H
#define _RHEOLEF_UBLAS_INVERT_H
///
/// This file is part of Rheolef.
///
/// Copyright (C) 2000-2009 Pierre Saramito <Pierre.Saramito@imag.fr>
///
/// Rheolef is free software; you can redistribute it and/or modify
/// it under the terms of the GNU General Public License as published by
/// the Free Software Foundation; either version 2 of the License, or
/// (at your option) any later version.
///
/// Rheolef 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 General Public License for more details.
///
/// You should have received a copy of the GNU General Public License
/// along with Rheolef; if not, write to the Free Software
/// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
///
/// =========================================================================
//
// The following code inverts the matrix input using LU-decomposition
// with backsubstitution of unit vectors.
// Reference: Numerical Recipies in C, 2nd ed., by Press, Teukolsky, Vetterling & Flannery.
//
// http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?action=browse&diff=1&id=LU_Matrix_Inversion
// Hope someone finds this useful. Regards, Fredrik Orderud.
//
// Last edited September 4, 2007 5:23 am
//
#include <boost/numeric/ublas/vector.hpp>
#include <boost/numeric/ublas/vector_proxy.hpp>
#include <boost/numeric/ublas/matrix.hpp>
#include <boost/numeric/ublas/triangular.hpp>
#include <boost/numeric/ublas/lu.hpp>
#include <boost/numeric/ublas/io.hpp>
namespace ublas = boost::numeric::ublas;
namespace rheolef {
// Matrix inversion routine.
// Uses lu_factorize and lu_substitute in uBLAS to invert a matrix
template<class T>
bool invert (const ublas::matrix<T>& input, ublas::matrix<T>& inverse) {
using namespace boost::numeric::ublas;
typedef permutation_matrix<std::size_t> pmatrix;
// create a working copy of the input
matrix<T> A(input);
// create a permutation matrix for the LU-factorization
pmatrix pm(A.size1());
// perform LU-factorization
int res = lu_factorize(A,pm);
if( res != 0 ) return false;
// create identity matrix of "inverse"
inverse.assign(ublas::identity_matrix<T>(A.size1()));
// backsubstitute to get the inverse
lu_substitute(A, pm, inverse);
return true;
}
template<class T>
boost::numeric::ublas::matrix<T>
invert(const boost::numeric::ublas::matrix<T> &m, bool &is_singular)
{
ublas::matrix<T> inv_m (m.size1(), m.size2());
is_singular = ! invert (m, inv_m);
return inv_m;
}
// http://archives.free.net.ph/message/20080909.064313.59c122c4.fr.html
template<class matrix_T>
double determinant(ublas::matrix_expression<matrix_T> const& mat_r) {
double det = 1.0;
matrix_T mLu(mat_r());
ublas::permutation_matrix<std::size_t> pivots(mat_r().size1() );
bool is_singular = lu_factorize(mLu, pivots);
if (!is_singular) {
for (std::size_t i = 0; i < pivots.size(); ++i) {
if (pivots(i) != i) {
det *= -1.0;
}
det *= mLu(i,i);
}
} else {
det = 0.0;
}
return det;
}
}// namespace rheolef
#endif // _RHEOLEF_UBLAS_INVERT_H
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