linbox
examples/det.C

Determinant of sparse matrix over Z or Zp.

/*
* examples/det.C
*
* Copyright (C) 2005, 2010 D. Saunders, J-G. Dumas
* ========LICENCE========
* This file is part of the library LinBox.
*
* LinBox 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 2.1 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
* ========LICENCE========
*/
#include <iostream>
using namespace LinBox;
using namespace std;
int main (int argc, char **argv)
{
commentator().setMaxDetailLevel (-1);
commentator().setMaxDepth (-1);
commentator().setReportStream (std::cerr);
if (argc <= 1 || argc > 3) {
cerr << "Usage: det <matrix-file-in-supported-format> [<p>]" << endl;
return -1;
}
if (argc == 2 ) {
// For a small integer matrix test, do "det data/mat2S".
// It is a 2 by 2 matrix with determinant = -2.
typedef Givaro::ZRing<Integer> Integers;
Integers ZZ;
ifstream input (argv[1]);
if (!input)
{ cerr << "Error opening matrix file " << argv[1] << endl;
return -1;
}
DenseMatrix<Integers> A(ZZ); A.read(input);
cout << "Matrix is " << A.rowdim() << " by " << A.coldim() << endl;
Integers::Element det_A;
det (det_A, A);
cout << "Determinant is ";
ZZ.write(cout, det_A) << endl;
}
if (argc == 3) {
typedef Givaro::Modular<double> Field;
double q = atof(argv[2]);
Field F(q);
ifstream input (argv[1]);
if (!input)
{ cerr << "Error opening matrix file " << argv[1] << endl;
return -1;
}
SparseMatrix<Field> B (F); B.read(input);
cout << "Matrix is " << B.rowdim() << " by " << B.coldim() << endl;
Field::Element det_B;
det (det_B, B);
cout << "Determinant is ";
F.write(cout, det_B) << " mod " << q << endl;
}
return 0;
}
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