examples/solve.C

/*
 * examples/solve.C
 *
 * Copyright (C) 2005, 2010 J-G Dumas, D. Saunders, P. Giorgi
 * ========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 <linbox/linbox-config.h>

#include <iostream>

#include <givaro/modular.h>
#include <givaro/zring.h>
#include <linbox/matrix/sparse-matrix.h>
#include <linbox/solutions/solve.h>
#include <linbox/util/matrix-stream.h>
#include <linbox/solutions/methods.h>

using namespace LinBox;

int main (int argc, char **argv)
{

    commentator().setMaxDetailLevel (-1);
    commentator().setMaxDepth (-1);
    commentator().setReportStream (std::cerr);


    if (argc < 2 || argc > 4) {
        std::cerr << "Usage: solve <matrix-file-in-supported-format> [<dense-vector-file>] [<p>]" << std::endl;
        return 0;
    }
    srand48( BaseTimer::seed() );

    std::ifstream input (argv[1]);
    if (!input) { std::cerr << "Error opening matrix file " << argv[1] << std::endl; return -1; }
    std::ifstream invect;

    bool createB = false;
    int ModComp = 0;
    if (argc == 2) {
        createB = true;
        ModComp = 0;
    }

    if (argc == 3) {
        invect.open (argv[2], std::ifstream::in);
        if (!invect) {
            createB = true;
            ModComp = 2;
        }
        else {
            createB = false;
            ModComp = 0;
        }
    }

    if (argc == 4) {
        ModComp = 3;
        invect.open (argv[2], std::ifstream::in);
        if (!invect) {
            createB = true;
        }
        else
            createB = false;
    }


    if (ModComp) {
        std::cout<<"Computation is done over Z/("<<atoi(argv[ModComp])<<")"<<std::endl;
        typedef Givaro::Modular<double> Field;
        double q = atof(argv[ModComp]);
        typedef DenseVector<Field> DenseVector ;
        Field F(q);
        MatrixStream< Field > ms ( F, input );
        SparseMatrix<Field> A (ms);  // A.write(std::cout);
        std::cout << "A is " << A.rowdim() << " by " << A.coldim() << std::endl;
        if (A.rowdim() <= 20 && A.coldim() <= 20) A.write(std::cerr << "A:=",Tag::FileFormat::Maple) << ';' << std::endl;
        DenseVector X(F, A.coldim()),B(F, A.rowdim());
        if (createB) {
            std::cerr << "Creating a random {-1,1} vector U, B is AU (to have a consistent system)" << std::endl;
            DenseVector U(F, A.coldim() );
            for(DenseVector::iterator it=U.begin();
                it != U.end(); ++it)
                if (drand48() <0.5)
                    F.assign(*it,F.mOne);
                else
                    F.assign(*it,F.one);
            A.apply(B,U);
        }
        else {
            for(DenseVector::iterator it=B.begin();
                it != B.end(); ++it)
                F.read(invect,*it);
        }

        // A.write(std::cout << "A: ") << std::endl;

        std::cout << "B is " << B << std::endl;

        Timer chrono;

        // Sparse Elimination
        std::cout << "Sparse Elimination" << std::endl;
        chrono.clear();
        chrono.start();
        Method::SparseElimination M;
        solve (X, A, B, M);
        chrono.stop();

        std::cout << "(Sparse Gauss) Solution is [";
        for(DenseVector::const_iterator it=X.begin();it != X.end(); ++it)
            F.write(std::cout, *it) << " ";
        std::cout << "]" << std::endl;
        std::cout << "CPU time (seconds): " << chrono.usertime() << std::endl<<std::endl;;

        // DenseElimination
        std::cout << "DenseElimination" << std::endl;
        chrono.start();
        solve (X, A, B, Method::DenseElimination());
        chrono.stop();

        std::cout << "(DenseElimination) Solution is [";
        for(DenseVector::const_iterator it=X.begin();it != X.end(); ++it)
            F.write(std::cout, *it) << " ";
        std::cout << "]" << std::endl;
        std::cout << "CPU time (seconds): " << chrono.usertime() << std::endl<< std::endl;

        // Wiedemann
        std::cout << "Blackbox" << std::endl;
        chrono.clear();
        chrono.start();
        solve (X, A, B, Method::Blackbox());
        chrono.stop();

        std::cout << "(Wiedemann) Solution is [";
        for(DenseVector::const_iterator it=X.begin();it != X.end(); ++it)
            F.write(std::cout, *it) << " ";
        std::cout << "]" << std::endl;
        std::cout << "CPU time (seconds): " << chrono.usertime() << std::endl<<std::endl;;
#if 0
        // Lanczos
        std::cout << "Lanczos" << std::endl;
        chrono.clear();
        chrono.start();
        solve (X, A, B, Method::Lanczos());
        chrono.stop();

        std::cout << "(Lanczos) Solution is [";
        for(DenseVector::const_iterator it=X.begin();it != X.end(); ++it)
            F.write(std::cout, *it) << " ";
        std::cout << "]" << std::endl;
        std::cout << "CPU time (seconds): " << chrono.usertime() << std::endl<< std::endl;


        // Block Lanczos
        std::cout << "Block Lanczos" << std::endl;
        Method::BlockLanczos MBL;
        MBL.preconditioner(Specifier::FULL_DIAGONAL);
        chrono.clear();
        chrono.start();
        solve (X, A, B, MBL);
        chrono.stop();

        std::cout << "(Block Lanczos) Solution is [";
        for(DenseVector::const_iterator it=X.begin();it != X.end(); ++it)
            F.write(std::cout, *it) << " ";
        std::cout << "]" << std::endl;
        std::cout << "CPU time (seconds): " << chrono.usertime() << std::endl<< std::endl;
#endif

    }
    else {
        std::cout<<"Computation is done over Q"<<std::endl;
        Givaro::ZRing<Integer> ZZ;
        typedef DenseVector<Givaro::ZRing<Integer> > DenseVector ;
        MatrixStream< Givaro::ZRing<Integer> > ms( ZZ, input );
        SparseMatrix<Givaro::ZRing<Integer> > A (ms);
        Givaro::ZRing<Integer>::Element d;
        std::cout << "A is " << A.rowdim() << " by " << A.coldim() << std::endl;
                if (A.rowdim() <= 20 && A.coldim() <= 20) A.write(std::cerr << "A:=",Tag::FileFormat::Maple) << ';' << std::endl;
        DenseVector X(ZZ, A.coldim()),B(ZZ, A.rowdim());

        if (createB) {
            std::cerr << "Creating a random {-1,1} vector U, B is AU" << std::endl;
            DenseVector U(ZZ, A.coldim() );
            for(DenseVector::iterator it=U.begin();
                it != U.end(); ++it)
                if (drand48() <0.5)
                    *it = -1;
                else
                    *it = 1;
            A.apply(B,U);
        }
        else {
            for(DenseVector::iterator it=B.begin();
                it != B.end(); ++it)
                invect >> *it;
        }

        std::cout << "B is " << B << std::endl;

        Timer chrono;
        // DenseElimination
        std::cout << "DenseElimination" << std::endl;
        chrono.start();
        solve (X, d, A, B, Method::DenseElimination());
        chrono.stop();

        std::cout << "(DenseElimination) Solution is [";
        for(DenseVector::const_iterator it=X.begin();it != X.end(); ++it)
        ZZ.write(std::cout, *it) << " ";
        std::cout << "] / ";
        ZZ.write(std::cout, d)<< std::endl;
        std::cout << "CPU time (seconds): " << chrono.usertime() << std::endl;

        // Sparse Elimination
        std::cout << "Sparse Elimination" << std::endl;
        chrono.start();
        solve (X, d, A, B, Method::SparseElimination());
        chrono.stop();

        std::cout << "(SparseElimination) Solution is [";
        for(DenseVector::const_iterator it=X.begin();it != X.end(); ++it)
            ZZ.write(std::cout, *it) << " ";
        std::cout << "] / ";
        ZZ.write(std::cout, d)<< std::endl;
        std::cout << "CPU time (seconds): " << chrono.usertime() << std::endl;

                        // Wiedemann
        std::cout << "Wiedemann" << std::endl;
        chrono.start();
        solve (X, d, A, B, Method::Wiedemann());
        chrono.stop();

        std::cout << "(Wiedemann) Solution is [";
        for(DenseVector::const_iterator it=X.begin();it != X.end(); ++it)
            ZZ.write(std::cout, *it) << " ";
        std::cout << "] / ";
        ZZ.write(std::cout, d) << std::endl;
        std::cout << "CPU time (seconds): " << chrono.usertime() << std::endl;



#if 0
        // Lanczos
        std::cout << "Lanczos" << std::endl;
        chrono.start();
        solve (X, d, A, B, Method::Lanczos());
        chrono.stop();

        std::cout << "(Lanczos) Solution is [";
        for(DenseVector::const_iterator it=X.begin();it != X.end(); ++it)
            ZZ.write(std::cout, *it) << " ";
        std::cout << "] / ";
        ZZ.write(std::cout, d) << std::endl;
        std::cout << "CPU time (seconds): " << chrono.usertime() << std::endl;


        // Block Lanczos
        std::cout << "Block Lanczos" << std::endl;
        chrono.clear();
        chrono.start();
        solve (X, d, A, B, Method::BlockLanczos());
        chrono.stop();

        std::cout << "(Block Lanczos) Solution is [";
        for(DenseVector::const_iterator it=X.begin();it != X.end(); ++it)
            ZZ.write(std::cout, *it) << " ";
        std::cout << "] / ";
        ZZ.write(std::cout, d) << std::endl;
        std::cout << "CPU time (seconds): " << chrono.usertime() << std::endl;
#endif
    }

    return 0;
}

// Local Variables:
// mode: C++
// tab-width: 4
// indent-tabs-mode: nil
// c-basic-offset: 4
// End:
// vim:sts=4:sw=4:ts=4:et:sr:cino=>s,f0,{0,g0,(0,\:0,t0,+0,=s