make() [1/3]

const Matrix * Matrix::make ( const FreeModule * target, const FreeModule * source, M2_arrayint deg, const engine_RawRingElementArray M )

static

Definition at line 93 of file matrix.cpp.

{
  const Ring *R = target->get_ring();
  auto D = R->degree_monoid();
  if (source->get_ring() != R)
    {
      ERROR("expected free modules over the same ring");
      return nullptr;
    }
  if (D->n_vars() != static_cast<int>(deg->len))
    {
      ERROR("expected degree of matrix to have %d entries", D->n_vars());
      return nullptr;
    }
 
  if (M != nullptr)
    {
      for (unsigned int i = 0; i < M->len; i++)
        {
          if (R != M->array[i]->get_ring())
            {
              ERROR("expected vectors in the same ring");
              return nullptr;
            }
        }
    }
 
  monomial degshift = D->make_one();
  D->from_expvector(deg->array, degshift);
  MatrixConstructor mat(target, source, degshift);
 
  if (M != nullptr)
    {
      unsigned int next = 0;
      for (int r = 0; r < target->rank(); r++)
        {
          for (int c = 0; c < source->rank(); c++)
            {
              mat.set_entry(r, c, M->array[next]->get_value());
              next++;
              if (next >= M->len) break;
            }
        }
    }
  return mat.to_matrix();
}

References Ring::degree_monoid(), ERROR, FreeModule, FreeModule::get_ring(), make(), Matrix(), MatrixConstructor, monomial, FreeModule::rank(), MatrixConstructor::set_entry(), and MatrixConstructor::to_matrix().