https://hal.archives-ouvertes.fr/hal-02128878
Tip revision: 4201397494d9af8b687117e8ff4d85a8944f5c5a authored by Software Heritage on 11 June 2019, 10:15:02 UTC
hal: Deposit 298 in collection hal
hal: Deposit 298 in collection hal
Tip revision: 4201397
ffpack-fgesv.C
/* Copyright (c) FFLAS-FFPACK
* Written by ZHU Hongguang <zhuhongguang2014@gmail.com>
* ========LICENCE========
* This file is part of the library FFLAS-FFPACK.
*
* FFLAS-FFPACK 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 <fflas-ffpack/fflas/fflas.h>
#include <givaro/modular.h>
#include <givaro/modular-balanced.h>
#include "fflas-ffpack/utils/fflas_io.h"
#include <fflas-ffpack/ffpack/ffpack.h>
#include <iostream>
using namespace FFLAS;
using namespace FFPACK;
int main(int argc, char** argv) {
typedef Givaro::Modular<float> Field;
Field F(17);
// Let A be a M times M square matrix of coefficients
const size_t M = 4, lda = M;
Field::Element_ptr A;
A = fflas_new(F,M,M);
// Fulfill the square matrix A so that A is invertible
F.assign(A[0], F.one);
F.assign (A[1],F.zero);
F.assign(A[2],F.one);
F.assign (A[3],F.zero);
F.assign(A[4],F.zero);
F.assign (A[5],F.one);
F.assign(A[6],F.zero);
F.assign (A[7],F.one);
F.assign(A[8],F.zero);
F.assign (A[9],F.zero);
F.assign(A[10],F.one);
F.assign (A[11],F.zero);
F.assign(A[12],F.zero);
F.assign (A[13],F.zero);
F.assign(A[14],(F.zero));
F.assign (A[15],F.one);
WriteMatrix(std::cout<<"A:="<<std::endl,F,M,M,A,lda)<<std::endl;
// Let X be a M times 2 matrix of variables
const size_t ldx = 2;
Field::Element_ptr x;
x = fflas_new(F,M,2);
fiszero (F, M, 2, x, ldx); //initialize all elements to zero
WriteMatrix(std::cout<<"x:="<<std::endl,F,M, 2, x, ldx)<<std::endl;
// Let b be a M times 2 matrix of solutions
const size_t ldb = 2;
Field::Element_ptr b;
b = fflas_new(F,M,2);
// Fulfill the matrix b with desired values
F.init(b[0],4);
F.init(b[1],4);
F.init(b[2],6);
F.init(b[3],3);
F.init(b[4],3);
F.init(b[5],6);
F.init(b[6],4);
F.init(b[7],4);
WriteMatrix(std::cout<<"b:="<<std::endl,F,M, 2, b, ldb)<<std::endl;
// make a copy of b into x
fassign(F,M,2,b,ldb,x,2);
WriteMatrix(std::cout<<"copied b:="<<std::endl,F,M, 2, x, ldx)<<std::endl;
//Solve the system
int state;
size_t rank = fgesv(F, FflasLeft, M, 2, A, lda, x, ldx, &state);
if(rank!=M)std::cout<<"Results are incorrect after the fgesv()!"<<std::endl;
WriteMatrix(std::cout<<"x:="<<std::endl,F,M, 2, x, ldx)<<std::endl;
// Let res be a M times 2 matrix
const size_t ldres = 2;
Field::Element_ptr res;
res = fflas_new(F,M,2);
fiszero (F, M, 2, res, ldres); //initialize all elements to zero
// Verify if A*x == b to confirm the found the solution
std::cout<<"Verification:"<<std::endl;
fgemm(F, FflasNoTrans, FflasNoTrans, M, 2, M, F.one, A, lda, x, ldx, F.zero, res, ldres);
WriteMatrix(std::cout<<"A*x:="<<std::endl,F,M,2,res,ldres)<<std::endl;
if( !fequal (F, M, 2, res, ldres, b, ldb) ) {
std::cout<<"Results are incorrect!"<<std::endl;
}
else
{
std::cout<<"Results are correct!"<<std::endl;
}
// Clearing up the memory
fflas_delete(A);
fflas_delete(x);
fflas_delete(b);
fflas_delete(res);
return 0;
}
/* -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
// vim:sts=4:sw=4:ts=4:et:sr:cino=>s,f0,{0,g0,(0,\:0,t0,+0,=s