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/*
Copyright (C) 2021-2021 Michele Martone
This file is part of librsb.
librsb 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 3 of the License, or
(at your option) any later version.
librsb 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 librsb; see the file COPYING.
If not, see <http://www.gnu.org/licenses/>.
*/
/*!
\ingroup rsb_doc_examples
\file
@author Michele Martone
@brief C++ example based on <rsb.hpp> assembling RsbMatrix by pieces.
\include assemble.cpp
*/
#include <rsb.hpp>
#include <vector>
#include <cassert>
#include <array>
using namespace rsb;
auto main() -> int {
RsbLib rsblib;
/*! [snip__RsbMatrix_Assemble] */
const rsb_coo_idx_t nrA { 4 }, ncA { 4 };
RsbMatrix<double> mtx(nrA,ncA); // begin matrix assembly
// insert elements of a tridiagonal matrix, one by one
for (auto i = 0; i < nrA; ++i )
for (auto j = i-1; j <= i+1; ++j )
if ( i >= 0 && i < nrA )
if ( j >= 0 && j < ncA )
mtx.set_val((i+1)*100+(j+1),i,j); // add entry
mtx.close(); // finish matrix assembly
assert(mtx.nnz() == 3 * nrA - 2);
/*! [snip__RsbMatrix_Assemble] */
mtx.file_save(nullptr); // print out
}
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