helmholtz_bem_2d_cyl.mex.cpp

// This file is a part of NiHu, a C++ BEM template library.
//
// Copyright (C) 2012-2014  Peter Fiala <fiala@hit.bme.hu>
// Copyright (C) 2012-2014  Peter Rucz <rucz@hit.bme.hu>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
#include "core/weighted_residual.hpp"
#include "util/mex_matrix.hpp"
#include "library/helmholtz_2d.hpp"
 
typedef NiHu::mex::real_matrix<double> dMatrix;
typedef NiHu::mex::complex_matrix<double> cMatrix;
 
void mexFunction(int nlhs, mxArray *lhs[], int nrhs, mxArray const *rhs[])
{
    dMatrix surf_nodes(rhs[0]), surf_elem(rhs[1]);
    auto surf_mesh = NiHu::create_mesh(surf_nodes, surf_elem, NiHu::line_1_tag());
 
    dMatrix field_nodes(rhs[2]), field_elem(rhs[3]);
    auto field_mesh = NiHu::create_mesh(field_nodes, field_elem, NiHu::line_1_tag());
 
    auto const &surf_sp = NiHu::constant_view(surf_mesh);
    auto const &field_sp = NiHu::dirac(NiHu::constant_view(field_mesh));
 
    size_t n = surf_sp.get_num_dofs();
    size_t m = field_sp.get_num_dofs();
    cMatrix Ls(n, n, lhs[0]), Lf(m, n, lhs[2]);
    cMatrix Ms(n, n, lhs[1]), Mf(m, n, lhs[3]);
 
    double k = *mxGetPr(rhs[4]);
    auto I = NiHu::identity_integral_operator();
    auto L = NiHu::create_integral_operator(NiHu::helmholtz_2d_SLP_kernel<double>(k));
    auto M = NiHu::create_integral_operator(NiHu::helmholtz_2d_DLP_kernel<double>(k));
 
    Ls << dirac(surf_sp) * L[surf_sp];
    Ms << dirac(surf_sp) * (M[surf_sp] + (-.5*I)[surf_sp]);
    Lf  << field_sp * L[surf_sp];
    Mf  << field_sp * M[surf_sp];
}