linbox
examples/sparseelimrank.C

Gaussian elimination Rank of sparse matrix over Z or Zp.

/*
* examples/sparseelimrank.C
*
* Copyright (C) 2006, 2010 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>
#include <vector>
#include <utility>
#include <givaro/zring.h>
#include <givaro/givrational.h>
#include <givaro/modular.h>
#include <linbox/field/gf2.h>
#include <linbox/blackbox/zero-one.h>
#include <linbox/solutions/rank.h>
#include <linbox/util/matrix-stream.h>
using namespace LinBox;
using namespace std;
int main (int argc, char **argv)
{
commentator().setMaxDetailLevel (-1);
commentator().setMaxDepth (-1);
commentator().setReportStream (std::cerr);
commentator().setBriefReportStream (std::cout);
if (argc < 2 || argc > 3)
{ cerr << "Usage: rank <matrix-file-in-supported-format> [<p>]" << endl; return -1; }
ifstream input (argv[1]);
if (!input) { cerr << "Error opening matrix file: " << argv[1] << endl; return -1; }
long unsigned int r;
if (argc == 2) { // rank over the integers.
/* We could pick a random prime and work mod that prime, But the point here
is that the rank function in solutions/ handles that issue. Our matrix here
is an integer matrix and our concept is that we are getting the rank of that
matrix by some blackbox magic inside linbox.
*/
Givaro::QField<Givaro::Rational> QQ;
SparseMatrix<Givaro::QField<Givaro::Rational>, SparseMatrixFormat::SparseSeq > A ( ms );
if (A.rowdim() <= 20 && A.coldim() <= 20) A.write(std::cerr << "A:=",Tag::FileFormat::Maple) << ';' << std::endl;
cout << "A is " << A.rowdim() << " by " << A.coldim() << endl;
cout << "Z Rank is " << r << endl;
}
if (argc == 3) {
double q = atof(argv[2]);
typedef Givaro::Modular<double> Field;
Field F(q);
MatrixStream<Field> ms( F, input );
SparseMatrix<Field, SparseMatrixFormat::SparseSeq > B (ms);
cout << "B is " << B.rowdim() << " by " << B.coldim() << endl;
if (B.rowdim() <= 20 && B.coldim() <= 20) B.write(cout) << endl;
// SE.strategy(Specifier::PIVOT_NONE);
// // using Sparse Elimination
// LinBox::rank (r, B, SE);
// if (B.rowdim() <= 20 && B.coldim() <= 20) B.write(cout) << endl;
// cout << "Rank is " << r << endl;
SE.strategy(Specifier::PIVOT_LINEAR);
// using Sparse Elimination
LinBox::rankin (r, B, SE);
if (B.rowdim() <= 20 && B.coldim() <= 20) B.write(cout) << endl;
F.write(cout << "Rank is " << r << " over ") << endl;
}
return 0;
}
// vim:sts=8:sw=8:ts=8:noet:sr:cino=>s,f0,{0,g0,(0,:0,t0,+0,=s
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