int main(int argc, char *argv[])
{
if (argc < 3) {
std::cout << "Usage: " << argv[0] << " input-matrix output-matrix" << std::endl;
return 1;
}
std::string fname_mat (argv[1]);
bool verbose (true);
// *** reading matrix in crs format from file
std::ifstream in(fname_mat.c_str(), std::ios::in | std::ios::binary);
double *A(NULL);
unsigned *iA(NULL), *jA(NULL), n;
if (in) {
if (verbose) {
std::cout << "reading matrix from " << fname_mat << " ... " << std::flush;
}
BaseLib::RunTime timer;
timer.start();
CS_read(in, n, iA, jA, A);
in.close();
timer.stop();
if (verbose) {
std::cout << "ok, " << timer.elapsed() << " s" << std::endl;
}
} else {
std::cout << "error reading matrix from " << fname_mat << std::endl;
}
unsigned nnz(iA[n]);
if (verbose) {
std::cout << "Parameters read: n=" << n << ", nnz=" << nnz << std::endl;
}
MathLib::CRSMatrix<double, unsigned> *mat (new MathLib::CRSMatrix<double, unsigned>(n, iA, jA, A));
const unsigned n_rows_cols_to_erase(300);
unsigned *rows_cols_to_erase(new unsigned[n_rows_cols_to_erase]);
for (unsigned k(0); k<n_rows_cols_to_erase; k++) {
rows_cols_to_erase[k] = (k+1)*2;
}
BaseLib::RunTime timer;
std::cout << "erasing " << n_rows_cols_to_erase << " rows and columns ... " << std::flush;
timer.start();
mat->eraseEntries(n_rows_cols_to_erase, rows_cols_to_erase);
timer.stop();
std::cout << "ok, " << timer.elapsed() << " s" << std::endl;
delete[] rows_cols_to_erase;
fname_mat = argv[2];
std::ofstream out (fname_mat.c_str(), std::ios::binary);
CS_write (out, mat->getNRows(), mat->getRowPtrArray(), mat->getColIdxArray(), mat->getEntryArray());
out.close();
std::cout << "wrote " << fname_mat << " with " << mat->getNRows() << " rows and " << mat->getRowPtrArray()[mat->getNRows()] << " entries" << std::endl;
delete mat;
}
void setKnownXi_ReduceSizeOfEQS(vector<IndexValue> &list_dirichlet_bc, MathLib::CRSMatrix<double, INDEX_TYPE> &eqsA, double* org_eqsRHS, double* org_eqsX, double** eqsRHS, double** eqsX, map<INDEX_TYPE,INDEX_TYPE> &map_solved_orgEqs)
{
const size_t n_org_rows = eqsA.getNRows();
vector<INDEX_TYPE> removed_rows(list_dirichlet_bc.size());
for (size_t i=0; i<list_dirichlet_bc.size(); i++) {
IndexValue &bc = list_dirichlet_bc.at(i);
const size_t id = bc.id;
const double val = bc.val;
removed_rows.at(i) = id;
//b_i -= A(i,k)*val, i!=k
for (size_t j=0; j<eqsA.getNCols(); j++)
org_eqsRHS[j] -= eqsA.getValue(j, id)*val;
//b_k = A_kk*val
org_eqsRHS[id] = val; //=eqsA(id, id)*val;
org_eqsX[id] = val; //=eqsA(id, id)*val;
}
//remove rows and columns
eqsA.eraseEntries(removed_rows.size(), &removed_rows[0]);
//remove X,RHS
(*eqsX) = new double[n_org_rows-removed_rows.size()];
(*eqsRHS) = new double[n_org_rows-removed_rows.size()];
size_t new_id = 0;
for (size_t i=0; i<n_org_rows; i++) {
if (find(removed_rows.begin(), removed_rows.end(), i)!=removed_rows.end()) continue;
(*eqsRHS)[new_id] = org_eqsRHS[i];
(*eqsX)[new_id] = org_eqsX[i];
map_solved_orgEqs[new_id] = i;
new_id++;
}
}
int main(int argc, char *argv[])
{
(void) argc;
(void) argv;
// *** reading matrix in crs format from file
std::string fname("/work/Thomas Fischer/data/testmat.bin");
// std::ifstream in(fname.c_str(), std::ios::binary);
MathLib::CRSMatrix<double, unsigned> *mat (new MathLib::CRSMatrix<double, unsigned>(fname));
/* double *A(NULL);
unsigned *iA(NULL), *jA(NULL), n;
if (in) {
std::cout << "reading matrix from " << fname << " ... " << std::flush;
CS_read(in, n, iA, jA, A);
in.close();
std::cout << " ok" << std::endl;
}
unsigned nnz(iA[n]);
*/
unsigned n (mat->getNRows());
std::cout << "Parameters read: n=" << n << std::endl;
double *x(new double[n]);
double *b(new double[n]);
// *** init start vector x
for (std::size_t k(0); k<n; k++) {
x[k] = 1.0;
}
// *** read rhs
fname = "/work/Thomas Fischer/data/rhs.dat";
std::ifstream in(fname.c_str());
if (in) {
read (in, n, b);
in.close();
} else {
std::cout << "problem reading rhs - initializing b with 1.0" << std::endl;
for (std::size_t k(0); k<n; k++) {
b[k] = 1.0;
}
}
std::cout << "solving system with CG method ... " << std::flush;
time_t start_time, end_time;
time(&start_time);
// double cg_time (cputime(0.0));
double eps (1.0e-6);
unsigned steps (4000);
CG (mat, b, x, eps, steps);
// cg_time = cputime(cg_time);
time(&end_time);
std::cout << " in " << steps << " iterations (residuum is " << eps << ") took " << /*cg_time <<*/ " sec time and " << (end_time-start_time) << " sec" << std::endl;
delete mat;
delete [] x;
delete [] b;
return 0;
}
void setKnownXi_ReduceSizeOfEQS(std::vector<IndexValue> &list_dirichlet_bc, MathLib::CRSMatrix<
double, INDEX_TYPE> &eqsA, double* org_eqsRHS, double* org_eqsX, double** eqsRHS,
double** eqsX, std::map<INDEX_TYPE, INDEX_TYPE> &map_solved_orgEqs)
{
const size_t n_org_rows = eqsA.getNRows();
std::vector<INDEX_TYPE> removed_rows(list_dirichlet_bc.size());
std::cout << "[BC] (transpose matrix) ... " << std::flush;
RunTimeTimer run_trans;
run_trans.start();
MathLib::CRSMatrix<double, INDEX_TYPE>* transpose_mat (eqsA.getTranspose());
run_trans.stop();
std::cout << run_trans.elapsed() << " s" << std::endl;
INDEX_TYPE const*const row_ptr (transpose_mat->getRowPtrArray());
INDEX_TYPE const*const col_idx (transpose_mat->getColIdxArray());
double const*const data (transpose_mat->getEntryArray());
for (size_t i = 0; i < list_dirichlet_bc.size(); i++) {
IndexValue &bc = list_dirichlet_bc.at(i);
const size_t id = bc.id;
const double val = bc.val;
removed_rows.at(i) = id;
//b_i -= A(i,k)*val, i!=k
// for (size_t j = 0; j < eqsA.getNCols(); j++)
// org_eqsRHS[j] -= eqsA.getValue(j, id) * val;
const INDEX_TYPE end(row_ptr[id+1]);
for (INDEX_TYPE k(row_ptr[id]); k<end; k++) {
const INDEX_TYPE j(col_idx[k]);
org_eqsRHS[j] -= data[j] * val;
}
//b_k = A_kk*val
org_eqsRHS[id] = val; //=eqsA(id, id)*val;
org_eqsX[id] = val; //=eqsA(id, id)*val;
}
delete transpose_mat;
//remove rows and columns
eqsA.eraseEntries(removed_rows.size(), &removed_rows[0]);
//remove X,RHS
(*eqsX) = new double[n_org_rows - removed_rows.size()];
(*eqsRHS) = new double[n_org_rows-removed_rows.size()];
size_t new_id = 0;
for (size_t i=0; i<n_org_rows; i++) {
if (std::find(removed_rows.begin(), removed_rows.end(), static_cast<unsigned>(i))!=removed_rows.end()) continue;
(*eqsRHS)[new_id] = org_eqsRHS[i];
(*eqsX)[new_id] = org_eqsX[i];
map_solved_orgEqs[new_id] = i;
new_id++;
}
}