linbox
examples/nullspacebasis.C

NullSpace of sparse matrix over GFq.nullspace is allocated m n.

/*
* examples/nullspacebasis.C
*
* Copyright (C) 2014 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 <givaro/gfq.h>
using namespace LinBox;
int main (int argc, char **argv)
{
if ( argc < 2 || argc > 4) {
std::cerr << "Usage to get a random null space basis over GF(p,k): <matrix-file-in-SMS-format> p [k]" << std::endl;
return -1;
}
std::ifstream input (argv[1]);
if (!input) { std::cerr << "Error opening matrix file " << argv[1] << std::endl; return -1; }
//typedef Givaro::Modular<int> Field;
typedef Givaro::GFqDom<int64_t> Field;
Field F(atoi(argv[2]),argc>3?atoi(argv[3]):1);
SparseMatrix<Field, SparseMatrixFormat::SparseSeq > B (F);
B.read (input);
std::cout << "B is " << B.rowdim() << " by " << B.coldim() << std::endl;
DenseMatrix<Field> NullSpace(F,B.coldim(),B.coldim());
GD.nullspacebasisin(NullSpace, B);
NullSpace.write( std::cerr << "X:=", Tag::FileFormat::Maple ) << ';' << std::endl;
std::cerr << "NullsSpace dimensions:" << NullSpace.rowdim() << 'x' << NullSpace.coldim() << std::endl;
return 0;
}