matrixsolve.C File Reference

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Functions
void	usage (const std::string &prog_name)
int	main (int argc, char **argv)

Function Documentation

main()

int main	(	int	argc,
		char **	argv
	)

Definition at line 33 of file matrixsolve.C.

References libMesh::LinearSolver< T >::build(), libMesh::SparseMatrix< T >::build(), libMesh::NumericVector< T >::build(), libMesh::TriangleWrapper::init(), libMesh::out, libMesh::Real, libMesh::LinearSolver< T >::solve(), and usage().

{
  LibMeshInit init(argc, argv);

  if (argc < 3)
    usage(argv[0]);

  // Create a GetPot object to parse the command line
  GetPot command_line (argc, argv);

  std::string matfile, rhsfile;
  if (command_line.search(1, "-m"))
    matfile = command_line.next(matfile);
  else
    usage(argv[0]);

  if (command_line.search(1, "-r"))
    rhsfile = command_line.next(rhsfile);
  else
    usage(argv[0]);

  auto mat = SparseMatrix<Number>::build(init.comm());

  LOG_CALL("mat.read()", "main", mat->read(matfile));

  libMesh::out << "Loaded " << mat->m() << " by " << mat->n() <<
    " matrix " << matfile << std::endl;

  auto rhs = NumericVector<Number>::build(init.comm()),
       solution = NumericVector<Number>::build(init.comm());

  LOG_CALL("rhs.read()", "main", rhs->read_matlab(rhsfile));

  libMesh::out << "Loaded length-" << rhs->size() <<
    " vector " << rhsfile << std::endl;

  solution->init(rhs->size(), rhs->local_size());

  auto solver = LinearSolver<Number>::build(init.comm());

  Real tol = 1e-9;
  if (command_line.search(1, "-t"))
    tol = command_line.next(tol);

  unsigned int n_iters = 1e3;
  if (command_line.search(1, "-n"))
    n_iters = command_line.next(n_iters);

  auto [iters, res] = solver->solve(*mat, *solution, *rhs, tol, n_iters);

  libMesh::out << "Finished in " << iters << " iterations with " << res
      << " residual " << std::endl;

  return 0;
}

usage()

void usage

(

const std::string &

prog_name

)

Definition at line 90 of file matrixsolve.C.

References libMesh::out.

Referenced by main().

{
  std::ostringstream helpList;
  helpList <<
    "Usage: " << prog_name <<
    " [options]\n"
    "\n"
    "options:\n"
    "    -m <string> Matrix filename (required)\n"
    "    -r <string> RHS Vector filename (required)\n"
    "    -t <tol>    Linear Solver tolerance (default 1e-9)\n"
    "    -n <n_iter> Linear Solver max iterations (default 1e3)\n";

  libMesh::out << helpList.str();
  exit(0);
}