support()

M2_arrayint PolyRing::support ( const ring_elem a ) const

virtual

Implements PolynomialRing.

Definition at line 339 of file poly.cpp.

{
  exponents_t EXP1 = ALLOCATE_EXPONENTS(exp_size);
  exponents_t EXP2 = ALLOCATE_EXPONENTS(exp_size);
  for (int i = 0; i < n_vars(); i++) EXP1[i] = 0;
  for (Nterm& t : f)
    {
      M_->to_expvector(t.monom, EXP2);
      exponents::lcm(n_vars(), EXP1, EXP2, EXP1);
    }
  int nelems = 0;
  for (int i = 0; i < n_vars(); i++)
    if (EXP1[i] > 0) nelems++;
  M2_arrayint result = M2_makearrayint(nelems);
  int next = 0;
  for (int i = 0; i < n_vars(); i++)
    if (EXP1[i] > 0) result->array[next++] = i;
  return result;
}

References ALLOCATE_EXPONENTS, PolynomialRing::exp_size, ExponentVector< int, true >::lcm(), M2_makearrayint(), PolynomialRing::M_, PolynomialRing::n_vars(), and result().