coeffs_of_vec()

vec coeffs_of_vec ( exponent_table * E, M2_arrayint vars, const FreeModule * F, vec f )

static

Definition at line 1807 of file matrix.cpp.

{
  if (f == nullptr) return nullptr;
  const PolynomialRing *P = F->get_ring()->cast_to_PolynomialRing();
  if (P == nullptr) return nullptr;
  const Monoid *M = P->getMonoid();
  monomial mon = M->make_one();
 
  // At this point, we know that we have a polynomial ring
  int nvars = M->n_vars();
  exponents_t exp = newarray_atomic(int, nvars);
  exponents_t scratch_exp = newarray_atomic(int, 1 + vars->len);
 
  vec result = nullptr;
  for (vec g = f; g != nullptr; g = g->next)
    {
      for (Nterm& h : g->coeff)
        {
          M->to_expvector(h.monom, exp);
          get_part_of_expvector(vars, exp, g->comp, scratch_exp);
          int val = static_cast<int>(exponent_table_get(E, scratch_exp));
          if (val > 0)
            {
              M->from_expvector(exp, mon);
              ring_elem t = P->make_flat_term(h.coeff, mon);
              vec v = P->make_vec(val - 1, t);
              v->next = result;
              result = v;
            }
        }
    }
  freemem(exp);
  freemem(scratch_exp);
  M->remove(mon);
  P->vec_sort(result);
  return result;
}

References Ring::cast_to_PolynomialRing(), Nterm::coeff, exponent_table_get(), freemem(), Monoid::from_expvector(), get_part_of_expvector(), FreeModule::get_ring(), PolynomialRing::getMonoid(), PolynomialRing::make_flat_term(), Monoid::make_one(), Ring::make_vec(), Nterm::monom, monomial, Monoid::n_vars(), newarray_atomic, Monoid::remove(), result(), Monoid::to_expvector(), and Ring::vec_sort().

Referenced by Matrix::coeffs().