rawHilbertBasis()

const Matrix * rawHilbertBasis

(

const Matrix *

C

)

Definition at line 60 of file cone.cpp.

{
  try
    {
      // TODO: Check that C is over ZZ
      // TODO: for cones over QQ, lift to ZZ first
      // TODO: Normaliz also supports algebraic cones defined over
      // algebraic number fields embedded in RR
      const Ring *R = C->get_ring();
      const size_t c = C->n_cols();  // rank of ambient lattice
      const size_t r = C->n_rows();  // number of cone rays
 
      auto rays = libnormaliz::Matrix<Integer>(r, c);
      for (size_t i = 0; i < r; i++)
        for (size_t j = 0; j < c; j++)
          rays[i][j] = static_cast<Integer>(C->elem(i, j).get_mpz());
 
      auto cone = libnormaliz::Cone<Integer>(libnormaliz::Type::cone, rays);
      // cone.compute(libnormaliz::ConeProperty::HilbertBasis,
      //              libnormaliz::ConeProperty::DefaultMode);
      auto HB = cone.getHilbertBasis();
      size_t n = HB.size();  // number of basis elements
 
      MatrixConstructor mat(R->make_FreeModule(n), c);
      for (size_t i = 0; i < n; i++)
        for (size_t j = 0; j < c; j++)
          {
            mpz_ptr z = newitem(__mpz_struct);
            mpz_init_set(z, HB[i][j].get_mpz_t());
            mpz_reallocate_limbs(z);
            mat.set_entry(i, j, ring_elem(z));
          }
 
      return mat.to_matrix();
  } catch (const exc::engine_error &e)
    {
      ERROR(e.what());
      return nullptr;
  }
}

References Matrix::elem(), ERROR, ring_elem::get_mpz(), Matrix::get_ring(), Ring::make_FreeModule(), Matrix, mpz_reallocate_limbs(), Matrix::n_cols(), Matrix::n_rows(), newitem, MatrixConstructor::set_entry(), and MatrixConstructor::to_matrix().